Programmable Thermostat with Ramp

[Whoey Louie]

On Tuesday, January 14, 2020 at 4:05:50 PM UTC-5, Rick C wrote:

On Tuesday, January 14, 2020 at 10:24:22 AM UTC-5, amdx wrote:
On 1/13/2020 4:28 PM, Rick C wrote:
On Monday, January 13, 2020 at 1:52:26 PM UTC-5, amdx wrote:
On 1/13/2020 12:08 PM, Rick C wrote:
On Monday, January 13, 2020 at 12:37:39 PM UTC-5, amdx wrote:
On 1/11/2020 11:03 AM, Rick C wrote:
On Saturday, January 11, 2020 at 8:49:50 AM UTC-5, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

Yes, you have posted about the limitations of your heatpump before. How is that relevant?

I suspect if you check with someone who knows, your backup heat will also run under two other conditions. One is the system detects ice on the outside coils. With a 40 degree cut off, your system might not worry with deicing. The other condition is when the system runs long enough that it decides the heat pump is not doing the job and switches to backup heat. Opps, another condition is if the inside temperature drops too far bellow the set temperature.

The first heat pump I owned was very, very simple. It had a two bulb thermostat. Set the temperature and bulb 1 would control the heat to keep the temperature. But if the room (hallway as the case may be) temperature dropped too far the second bulb switch would close and the backup heat would come on.

That is the condition I am trying to avoid with a thermostat which ramps the temperature up slowly enough to not kick in the backup heat.

I don't know of any heat pump that isn't set to work that way. Ask your installer. With the last system I bought I found I could not even get info from the company who made it. They always referred me to the "installer", like I was not worthy of information.


My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat.

I suspect there is a wire from the thermostat to the control board,
that develops an output when there is a high delta, this output tells

the control board to turn on Auxiliary heat.

The truth may lie elsewhere, but that's my analysis.


On page 47 of the Thermostat manual, if this is the manual,
http://www.utcccs-cdn.com/hvac/docs/1009/Public/04/OM-TPPACA-01.pdf
It says,

"SPECIAL FEATURES Hybrid Heat (heat pump with a furnace system
only)This thermostat works with the Carrier Hybrid Heat systems
offering maximum comfort and economy by automatically controlling
whether your system delivers heating with the heat pump, with the
furnace, or with both options working together."


Page 52
Hybrid Heat (heat pump with a furnace system only)page 47........This
Carrier heating and cooling system concept offers maximum
comfort and economy. When a Hybrid Heat system is installed,
the thermostat automatically controls whether your system delivers
heating with the heat pump, with the furnace,or with both options
working together.
Mikek

Doesn't say anything about electric back up vs. oil, etc...

One very good reason to not run the heat pump with the backup electric heat is the power required.

Why are you arguing that. I understand why you are trying to shut down
the auxiliary heat.

I'm saying the thermostat might not run both heats at the same time if the back up is electric because it would be a very large load at one time, 15 kW.


They have separate breakers, but the electric coils in my house are 10
kW or 40 amps requiring a 50 amp circuit. The outside unit would
require a 30 amp breaker. Just how much can you wire into a panel
before it becomes a problem? If the kitchen were drawing 5 kW or more,
the hot water heater was running at 10 kW (or more) and the dryer was
running at 8 kW, that's pretty durn close to the house hold max. Throw
in an iron fire up the microwave and a few light bulbs and the main
breaker might blow. One of my other houses, only having 100 amp
service, might have blown the main breaker before the dryer was turned
on, but for the fact it has oil backup.

Not helpful info.

So, do you think or can you find out, if the Thermostat has a separate
output when the thermostat has a high differential to fire up the oil
furnace?
Mikek

I took the thermostat off the mount and took some photos. Maybe I can dig up a manual. I have no other way of knowing what the thermostat will do, but I can assure you that there is not a special output for "high differential temperature". There is a signal to turn on the heat pump and a signal to run the electric coils. The furnace may or may not cut off the heat pump when the coils are on regardless of what the thermostat does.

I appreciate the help, but I'm not looking for someone to reverse engineer my heating system. Originally I was asking if anyone knew about a thermostat that would ramp up the temperature in a way that would not trigger the back up heat.

What is triggering the backup heat?

The only way to determine that is to instrument the whole thing and make measurements. I've not done that because it doesn't change the solution. The backup is coming on either because the temperature is too far from the set point, or because the heat has been running too long. The former can only be from the thermostat, the latter could be implemented in either.


Does it just come on when the Heat pump comes on?

???

Probably no, I think you said it only comes on with either a
long run of the heat pump, or if the system has been off a long time.
One or the other, could you define that better for me?

Nope, I don't know. I've not opened the furnace and put a volt meter on the various components to see exactly when what runs. I don't plan to either. Not useful info.

The thermostat doesn't have an indicator that tells you when aux heat
is on? Seems unusual, that's a pretty good thermostat, not some
junk. Even without that, you could easily tell if it works like seems
logical, which is aux heat supplements the heat pump or if it works like
you say it might, which is when aux comes on, it turns off the heat pump.
Very easy to figure that out. When it's a moderate day, set the temp up 5 deg
and see what happens. Either the heat pump shuts off or it keeps running.
I would think you would know which it is just from how's it's behaved.

What would cause you to want the oil furnace to come on?

When it is needed, but I don't have an oil furnace in this house. It has electric backup.


Can you you just put an on off switch in the oil furnace
turn on signal line?
That way, if you want oil heat just flip the switch.

Ok, you have completely missed the trolley and are headed to city center of off the mark ville.


If I have to roll my own thermostat I'm sure I can figure out what I
need to know to make it work.

The connector has the standard labeling of thermostats. The model is TCONT802AS32DAA Trane. I found manuals for it but they don't offer a lot of insight. I think a lot of this stuff is cut and dried and hasn't changed in 50 years or more. So they don't tell you any of the standard assumptions in the manuals.

Have you looked at this page?
https://www.manualslib.com/manual/461448/Trane-Tcont802as32da.html?page=18#manual


Does it apply to your thermostat setup?

Seems to.


I'm especially curious about #5.
#5. Choose appropriate Balance Point Temperature
in Installer Setup Number 0350.

Not sure what you are talking about "Balance Point Temperature". It says 0350 is for "Heat Pump Compressor Lockout". Doesn't sound useful to me.

Find out if it's set to lockout the aux heat above an outside temp and if so,
what temp it's set to. If it has an outside temp sensor and you set it
to 35F, that will eliminate your issue whenever the temp is above 35F,
which is when you can easily do without aux. It's setting 0360.

There might be more info to glean from this thermostat setup page.
https://www.manualslib.com/manual/461448/Trane-Tcont802as32da.html?page=12#manual

I haven't found anything other than settings that have already been dealt with.

--

Rick C.

--++ Get 1,000 miles of free Supercharging
--++ Tesla referral code - https://ts.la/richard11209

 

[amdx]

On 1/14/2020 3:05 PM, Rick C wrote:

On Tuesday, January 14, 2020 at 10:24:22 AM UTC-5, amdx wrote:
On 1/13/2020 4:28 PM, Rick C wrote:
On Monday, January 13, 2020 at 1:52:26 PM UTC-5, amdx wrote:
On 1/13/2020 12:08 PM, Rick C wrote:
On Monday, January 13, 2020 at 12:37:39 PM UTC-5, amdx wrote:
On 1/11/2020 11:03 AM, Rick C wrote:
On Saturday, January 11, 2020 at 8:49:50 AM UTC-5, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

Yes, you have posted about the limitations of your heatpump before. How is that relevant?

I suspect if you check with someone who knows, your backup heat will also run under two other conditions. One is the system detects ice on the outside coils. With a 40 degree cut off, your system might not worry with deicing. The other condition is when the system runs long enough that it decides the heat pump is not doing the job and switches to backup heat. Opps, another condition is if the inside temperature drops too far bellow the set temperature.

The first heat pump I owned was very, very simple. It had a two bulb thermostat. Set the temperature and bulb 1 would control the heat to keep the temperature. But if the room (hallway as the case may be) temperature dropped too far the second bulb switch would close and the backup heat would come on.

That is the condition I am trying to avoid with a thermostat which ramps the temperature up slowly enough to not kick in the backup heat.

I don't know of any heat pump that isn't set to work that way. Ask your installer. With the last system I bought I found I could not even get info from the company who made it. They always referred me to the "installer", like I was not worthy of information.


My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat.

I suspect there is a wire from the thermostat to the control board,
that develops an output when there is a high delta, this output tells

the control board to turn on Auxiliary heat.

The truth may lie elsewhere, but that's my analysis.


On page 47 of the Thermostat manual, if this is the manual,
http://www.utcccs-cdn.com/hvac/docs/1009/Public/04/OM-TPPACA-01.pdf
It says,

"SPECIAL FEATURES Hybrid Heat (heat pump with a furnace system
only)This thermostat works with the Carrier Hybrid Heat systems
offering maximum comfort and economy by automatically controlling
whether your system delivers heating with the heat pump, with the
furnace, or with both options working together."


Page 52
Hybrid Heat (heat pump with a furnace system only)page 47........This
Carrier heating and cooling system concept offers maximum
comfort and economy. When a Hybrid Heat system is installed,
the thermostat automatically controls whether your system delivers
heating with the heat pump, with the furnace,or with both options
working together.
Mikek

Doesn't say anything about electric back up vs. oil, etc...

One very good reason to not run the heat pump with the backup electric heat is the power required.

Why are you arguing that. I understand why you are trying to shut down
the auxiliary heat.

I'm saying the thermostat might not run both heats at the same time if the back up is electric because it would be a very large load at one time, 15 kW.


They have separate breakers, but the electric coils in my house are 10
kW or 40 amps requiring a 50 amp circuit. The outside unit would
require a 30 amp breaker. Just how much can you wire into a panel
before it becomes a problem? If the kitchen were drawing 5 kW or more,
the hot water heater was running at 10 kW (or more) and the dryer was
running at 8 kW, that's pretty durn close to the house hold max. Throw
in an iron fire up the microwave and a few light bulbs and the main
breaker might blow. One of my other houses, only having 100 amp
service, might have blown the main breaker before the dryer was turned
on, but for the fact it has oil backup.

Not helpful info.

So, do you think or can you find out, if the Thermostat has a separate
output when the thermostat has a high differential to fire up the oil
furnace?
Mikek

I took the thermostat off the mount and took some photos. Maybe I can dig up a manual. I have no other way of knowing what the thermostat will do, but I can assure you that there is not a special output for "high differential temperature". There is a signal to turn on the heat pump and a signal to run the electric coils. The furnace may or may not cut off the heat pump when the coils are on regardless of what the thermostat does.

I appreciate the help, but I'm not looking for someone to reverse engineer my heating system. Originally I was asking if anyone knew about a thermostat that would ramp up the temperature in a way that would not trigger the back up heat.

What is triggering the backup heat?

The only way to determine that is to instrument the whole thing and make measurements. I've not done that because it doesn't change the solution. The backup is coming on either because the temperature is too far from the set point, or because the heat has been running too long. The former can only be from the thermostat, the latter could be implemented in either.


Does it just come on when the Heat pump comes on?

???

Probably no, I think you said it only comes on with either a
long run of the heat pump, or if the system has been off a long time.
One or the other, could you define that better for me?

Nope, I don't know. I've not opened the furnace and put a volt meter on the various components to see exactly when what runs. I don't plan to either. Not useful info.


What would cause you to want the oil furnace to come on?

When it is needed, but I don't have an oil furnace in this house. It has electric backup.


Can you you just put an on off switch in the oil furnace
turn on signal line?
That way, if you want oil heat just flip the switch.

Ok, you have completely missed the trolley and are headed to city center of off the mark ville.

OK sorry, I went back and that was Win's post about oil furnace not yours.

You have said several times you want the aux heat to come on "when it's
needed" What is your criteria for when it's needed.

AH, I did find this,

2. The thermostat is calling for a 3° or higher temperature rise.

Most heat pump systems are designed to automatically switch to AUX heat
when the indoor temperature is 3 degrees colder than the thermostat
setting.

For example, let’s say that you wake up to a cold home (62° F) and
immediately raise the thermostat to 68°. Because the temperature rise is
more than 3 degrees (it’s 6 degrees in this scenario), the system will
automatically turn on the AUX heat to help your home meet the desired
temperature faster.

So first, check to see if your thermostat only says AUX when you raise
the thermostat 3 degrees or higher than the current temperature of your
home. If so, that’s normal. But here’s the problem: it’s still
expensive. So, if you want to cut down on your energy bills, try
limiting how often you raise the thermostat more than 3°

https://georgebrazilhvac.com/blog/my-heat-pumps-aux-heat-keeps-coming-on

Mikek

If I have to roll my own thermostat I'm sure I can figure out what I
need to know to make it work.

The connector has the standard labeling of thermostats. The model is TCONT802AS32DAA Trane. I found manuals for it but they don't offer a lot of insight. I think a lot of this stuff is cut and dried and hasn't changed in 50 years or more. So they don't tell you any of the standard assumptions in the manuals.

Have you looked at this page?
https://www.manualslib.com/manual/461448/Trane-Tcont802as32da.html?page=18#manual


Does it apply to your thermostat setup?

Seems to.


I'm especially curious about #5.
#5. Choose appropriate Balance Point Temperature
in Installer Setup Number 0350.

Not sure what you are talking about "Balance Point Temperature". It says 0350 is for "Heat Pump Compressor Lockout". Doesn't sound useful to me.


There might be more info to glean from this thermostat setup page.
https://www.manualslib.com/manual/461448/Trane-Tcont802as32da.html?page=12#manual

I haven't found anything other than settings that have already been dealt with.

 

[amdx]

On 1/14/2020 6:09 PM, Rick C wrote:

On Tuesday, January 14, 2020 at 5:30:05 PM UTC-5, amdx wrote:
On 1/14/2020 3:05 PM, Rick C wrote:
On Tuesday, January 14, 2020 at 10:24:22 AM UTC-5, amdx wrote:
On 1/13/2020 4:28 PM, Rick C wrote:
On Monday, January 13, 2020 at 1:52:26 PM UTC-5, amdx wrote:
On 1/13/2020 12:08 PM, Rick C wrote:
On Monday, January 13, 2020 at 12:37:39 PM UTC-5, amdx wrote:
On 1/11/2020 11:03 AM, Rick C wrote:
On Saturday, January 11, 2020 at 8:49:50 AM UTC-5, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

Yes, you have posted about the limitations of your heatpump before. How is that relevant?

I suspect if you check with someone who knows, your backup heat will also run under two other conditions. One is the system detects ice on the outside coils. With a 40 degree cut off, your system might not worry with deicing. The other condition is when the system runs long enough that it decides the heat pump is not doing the job and switches to backup heat. Opps, another condition is if the inside temperature drops too far bellow the set temperature.

The first heat pump I owned was very, very simple. It had a two bulb thermostat. Set the temperature and bulb 1 would control the heat to keep the temperature. But if the room (hallway as the case may be) temperature dropped too far the second bulb switch would close and the backup heat would come on.

That is the condition I am trying to avoid with a thermostat which ramps the temperature up slowly enough to not kick in the backup heat.

I don't know of any heat pump that isn't set to work that way. Ask your installer. With the last system I bought I found I could not even get info from the company who made it. They always referred me to the "installer", like I was not worthy of information.


My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat.

I suspect there is a wire from the thermostat to the control board,
that develops an output when there is a high delta, this output tells

the control board to turn on Auxiliary heat.

The truth may lie elsewhere, but that's my analysis.


On page 47 of the Thermostat manual, if this is the manual,
http://www.utcccs-cdn.com/hvac/docs/1009/Public/04/OM-TPPACA-01.pdf
It says,

"SPECIAL FEATURES Hybrid Heat (heat pump with a furnace system
only)This thermostat works with the Carrier Hybrid Heat systems
offering maximum comfort and economy by automatically controlling
whether your system delivers heating with the heat pump, with the
furnace, or with both options working together."


Page 52
Hybrid Heat (heat pump with a furnace system only)page 47........This
Carrier heating and cooling system concept offers maximum
comfort and economy. When a Hybrid Heat system is installed,
the thermostat automatically controls whether your system delivers
heating with the heat pump, with the furnace,or with both options
working together.
Mikek

Doesn't say anything about electric back up vs. oil, etc...

One very good reason to not run the heat pump with the backup electric heat is the power required.

Why are you arguing that. I understand why you are trying to shut down
the auxiliary heat.

I'm saying the thermostat might not run both heats at the same time if the back up is electric because it would be a very large load at one time, 15 kW.


They have separate breakers, but the electric coils in my house are 10
kW or 40 amps requiring a 50 amp circuit. The outside unit would
require a 30 amp breaker. Just how much can you wire into a panel
before it becomes a problem? If the kitchen were drawing 5 kW or more,
the hot water heater was running at 10 kW (or more) and the dryer was
running at 8 kW, that's pretty durn close to the house hold max. Throw
in an iron fire up the microwave and a few light bulbs and the main
breaker might blow. One of my other houses, only having 100 amp
service, might have blown the main breaker before the dryer was turned
on, but for the fact it has oil backup.

Not helpful info.

So, do you think or can you find out, if the Thermostat has a separate
output when the thermostat has a high differential to fire up the oil
furnace?
Mikek

I took the thermostat off the mount and took some photos. Maybe I can dig up a manual. I have no other way of knowing what the thermostat will do, but I can assure you that there is not a special output for "high differential temperature". There is a signal to turn on the heat pump and a signal to run the electric coils. The furnace may or may not cut off the heat pump when the coils are on regardless of what the thermostat does.

I appreciate the help, but I'm not looking for someone to reverse engineer my heating system. Originally I was asking if anyone knew about a thermostat that would ramp up the temperature in a way that would not trigger the back up heat.

What is triggering the backup heat?

The only way to determine that is to instrument the whole thing and make measurements. I've not done that because it doesn't change the solution. The backup is coming on either because the temperature is too far from the set point, or because the heat has been running too long. The former can only be from the thermostat, the latter could be implemented in either.


Does it just come on when the Heat pump comes on?

???

Probably no, I think you said it only comes on with either a
long run of the heat pump, or if the system has been off a long time.
One or the other, could you define that better for me?

Nope, I don't know. I've not opened the furnace and put a volt meter on the various components to see exactly when what runs. I don't plan to either. Not useful info.


What would cause you to want the oil furnace to come on?

When it is needed, but I don't have an oil furnace in this house. It has electric backup.


Can you you just put an on off switch in the oil furnace
turn on signal line?
That way, if you want oil heat just flip the switch.

Ok, you have completely missed the trolley and are headed to city center of off the mark ville.

OK sorry, I went back and that was Win's post about oil furnace not yours.

You have said several times you want the aux heat to come on "when it's
needed" What is your criteria for when it's needed.

AH, I did find this,

2. The thermostat is calling for a 3° or higher temperature rise.

Most heat pump systems are designed to automatically switch to AUX heat
when the indoor temperature is 3 degrees colder than the thermostat
setting.

For example, let’s say that you wake up to a cold home (62° F) and
immediately raise the thermostat to 68°. Because the temperature rise is
more than 3 degrees (it’s 6 degrees in this scenario), the system will
automatically turn on the AUX heat to help your home meet the desired
temperature faster.

So first, check to see if your thermostat only says AUX when you raise
the thermostat 3 degrees or higher than the current temperature of your
home. If so, that’s normal. But here’s the problem: it’s still
expensive. So, if you want to cut down on your energy bills, try
limiting how often you raise the thermostat more than 3°

And the light bulb finally comes on. Now you fully understand the problem I am trying to deal with.

Before you get to flippant with your comments, this was my very first post.

" My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat."
I'm done.
Mikek

 

[Rick C]

On Tuesday, January 14, 2020 at 5:30:05 PM UTC-5, amdx wrote:

On 1/14/2020 3:05 PM, Rick C wrote:
On Tuesday, January 14, 2020 at 10:24:22 AM UTC-5, amdx wrote:
On 1/13/2020 4:28 PM, Rick C wrote:
On Monday, January 13, 2020 at 1:52:26 PM UTC-5, amdx wrote:
On 1/13/2020 12:08 PM, Rick C wrote:
On Monday, January 13, 2020 at 12:37:39 PM UTC-5, amdx wrote:
On 1/11/2020 11:03 AM, Rick C wrote:
On Saturday, January 11, 2020 at 8:49:50 AM UTC-5, Winfield Hill wrote:
Rick C wrote...

My heatpump runs anytime the temperature is above 40F
= 4.4C (this is adjustable). The thermostat calls for
"aux" heat (oil furnace) when the outside temperature
is below that. When aux heat runs, the heatpump is
entirely off. It's a 2014 Carrier "edge" thermostat.

Yes, you have posted about the limitations of your heatpump before. How is that relevant?

I suspect if you check with someone who knows, your backup heat will also run under two other conditions. One is the system detects ice on the outside coils. With a 40 degree cut off, your system might not worry with deicing. The other condition is when the system runs long enough that it decides the heat pump is not doing the job and switches to backup heat. Opps, another condition is if the inside temperature drops too far bellow the set temperature.

The first heat pump I owned was very, very simple. It had a two bulb thermostat. Set the temperature and bulb 1 would control the heat to keep the temperature. But if the room (hallway as the case may be) temperature dropped too far the second bulb switch would close and the backup heat would come on.

That is the condition I am trying to avoid with a thermostat which ramps the temperature up slowly enough to not kick in the backup heat.

I don't know of any heat pump that isn't set to work that way. Ask your installer. With the last system I bought I found I could not even get info from the company who made it. They always referred me to the "installer", like I was not worthy of information.


My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat.

I suspect there is a wire from the thermostat to the control board,
that develops an output when there is a high delta, this output tells

the control board to turn on Auxiliary heat.

The truth may lie elsewhere, but that's my analysis.


On page 47 of the Thermostat manual, if this is the manual,
http://www.utcccs-cdn.com/hvac/docs/1009/Public/04/OM-TPPACA-01.pdf
It says,

"SPECIAL FEATURES Hybrid Heat (heat pump with a furnace system
only)This thermostat works with the Carrier Hybrid Heat systems
offering maximum comfort and economy by automatically controlling
whether your system delivers heating with the heat pump, with the
furnace, or with both options working together."


Page 52
Hybrid Heat (heat pump with a furnace system only)page 47........This
Carrier heating and cooling system concept offers maximum
comfort and economy. When a Hybrid Heat system is installed,
the thermostat automatically controls whether your system delivers
heating with the heat pump, with the furnace,or with both options
working together.
Mikek

Doesn't say anything about electric back up vs. oil, etc...

One very good reason to not run the heat pump with the backup electric heat is the power required.

Why are you arguing that. I understand why you are trying to shut down
the auxiliary heat.

I'm saying the thermostat might not run both heats at the same time if the back up is electric because it would be a very large load at one time, 15 kW.


They have separate breakers, but the electric coils in my house are 10
kW or 40 amps requiring a 50 amp circuit. The outside unit would
require a 30 amp breaker. Just how much can you wire into a panel
before it becomes a problem? If the kitchen were drawing 5 kW or more,
the hot water heater was running at 10 kW (or more) and the dryer was
running at 8 kW, that's pretty durn close to the house hold max. Throw
in an iron fire up the microwave and a few light bulbs and the main
breaker might blow. One of my other houses, only having 100 amp
service, might have blown the main breaker before the dryer was turned
on, but for the fact it has oil backup.

Not helpful info.

So, do you think or can you find out, if the Thermostat has a separate
output when the thermostat has a high differential to fire up the oil
furnace?
Mikek

I took the thermostat off the mount and took some photos. Maybe I can dig up a manual. I have no other way of knowing what the thermostat will do, but I can assure you that there is not a special output for "high differential temperature". There is a signal to turn on the heat pump and a signal to run the electric coils. The furnace may or may not cut off the heat pump when the coils are on regardless of what the thermostat does.

I appreciate the help, but I'm not looking for someone to reverse engineer my heating system. Originally I was asking if anyone knew about a thermostat that would ramp up the temperature in a way that would not trigger the back up heat.

What is triggering the backup heat?

The only way to determine that is to instrument the whole thing and make measurements. I've not done that because it doesn't change the solution. The backup is coming on either because the temperature is too far from the set point, or because the heat has been running too long. The former can only be from the thermostat, the latter could be implemented in either.


Does it just come on when the Heat pump comes on?

???

Probably no, I think you said it only comes on with either a
long run of the heat pump, or if the system has been off a long time.
One or the other, could you define that better for me?

Nope, I don't know. I've not opened the furnace and put a volt meter on the various components to see exactly when what runs. I don't plan to either. Not useful info.


What would cause you to want the oil furnace to come on?

When it is needed, but I don't have an oil furnace in this house. It has electric backup.


Can you you just put an on off switch in the oil furnace
turn on signal line?
That way, if you want oil heat just flip the switch.

Ok, you have completely missed the trolley and are headed to city center of off the mark ville.

OK sorry, I went back and that was Win's post about oil furnace not yours..

You have said several times you want the aux heat to come on "when it's
needed" What is your criteria for when it's needed.

AH, I did find this,

2. The thermostat is calling for a 3° or higher temperature rise.

Most heat pump systems are designed to automatically switch to AUX heat
when the indoor temperature is 3 degrees colder than the thermostat
setting.

For example, let’s say that you wake up to a cold home (62° F) and
immediately raise the thermostat to 68°. Because the temperature rise is
more than 3 degrees (it’s 6 degrees in this scenario), the system will
automatically turn on the AUX heat to help your home meet the desired
temperature faster.

So first, check to see if your thermostat only says AUX when you raise
the thermostat 3 degrees or higher than the current temperature of your
home. If so, that’s normal. But here’s the problem: it’s still
expensive. So, if you want to cut down on your energy bills, try
limiting how often you raise the thermostat more than 3°

And the light bulb finally comes on. Now you fully understand the problem I am trying to deal with.

I know how heat pumps are intended to operate. They use aux heat for some or all of these things depending on the maker.

1) Outside temp below some setting.

2) Inside temp below set point by some amount.

3) Thermostat calls for heat but still not up to temp after some time.

4) Defrosting outside coils.

5) Some reason I'm not recalling at this moment.

When the program setting turns the heat back up either reason 2 or 3 may result in the aux heat coming on. I don't want that. Once it reaches the new set point it should then continue operating as it did before.

My intent in this thread is to figure out if there is a thermostat that manages the set point in a way that reason 2 and 3 are not invoked. I'm really not trying to redesign a thermostat. That would be my last resort and likely would not do it even then.


http://arius.com/photos/Trane_thermostat_wiring_med.png

This shows labeling for all the wires that are connected in my furnace. Y turns on the compressor, so rather than being for cooling it turns on the heat on a heat pump and W turns on the aux heat.

There is no outdoor thermometer connected to the thermostat, so it can't do anything based on outdoor temperatures.

So that should finally answer everyone's questions. I'd still like to find a thermostat that lets me not have this problem when turning the heat back on for ToU.

--

Rick C.

-+-- Get 1,000 miles of free Supercharging
-+-- Tesla referral code - https://ts.la/richard11209

 

[Rick C]

On Tuesday, January 14, 2020 at 7:31:25 PM UTC-5, amdx wrote:

Before you get to flippant with your comments, this was my very first post.

" My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat."
I'm done.
Mikek

I don't know why you are ticked. It has been mentioned many times that the aux heat may kick in for several different reasons. That is not my concern and it never has been. I'm not trying to reverse engineer the thermostat.. It has never been about that as I've said any number of times.

I just wanted to ask if anyone knew of a thermostat that properly adjusts the set temperature so as to NOT turn on the aux heat. But everyone ignores my request. From the first post, "I'm wondering if anyone makes a programmable thermostat that deals with this issue."

Anyway, seems the answer is, "No, no one knows anything about a thermostat that won't trigger the aux heat when bringing up the set temp five degrees"..

Sorry you are upset. Thanks anyway.

--

Rick C.

-+-+ Get 1,000 miles of free Supercharging
-+-+ Tesla referral code - https://ts.la/richard11209

 

[amdx]

On 1/14/2020 7:31 PM, Rick C wrote:

On Tuesday, January 14, 2020 at 7:31:25 PM UTC-5, amdx wrote:

Before you get to flippant with your comments, this was my very first post.

" My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat."
I'm done.
Mikek

I don't know why you are ticked. It has been mentioned many times that the aux heat may kick in for several different reasons. That is not my concern and it never has been. I'm not trying to reverse engineer the thermostat. It has never been about that as I've said any number of times.

I just wanted to ask if anyone knew of a thermostat that properly adjusts the set temperature so as to NOT turn on the aux heat. But everyone ignores my request. From the first post, "I'm wondering if anyone makes a programmable thermostat that deals with this issue."

Anyway, seems the answer is, "No, no one knows anything about a thermostat that won't trigger the aux heat when bringing up the set temp five degrees".

Sorry you are upset. Thanks anyway.

Ok, one more, I don't know your Tou schedule so I'm just picking times.
Does your existing thermostat have enough programmable times to allow
you to say Turn on at 6am and warm the house to 64* then at 7am warm the
house to 67*, then at 8am warm the house to 70*. Might not take an hour
to warm the house 3*.
Or if your delta is 3* to cause aux to work, them make the difference
2*, 63*, 65*, 67*, and 69* over what ever period of time it takes to
warm the house 2* each run.
No, I don't know of a thermostat that will solve you problem
Mikek

If you had one temperature where you would want the Aux to run,
say 60 degrees. You could put a Mechanical 60 degree 'open on temp rise'
switch in the thermometer wire that tells the control board to turn on
the aux heat. That way the aux would never run unless the house temp was
below 60 degrees. I have no clue if that works for you because you never
gave me a good answer to, When do you want the aux heat to run?

 

[Rick C]

On Tuesday, January 14, 2020 at 9:28:55 PM UTC-5, amdx wrote:

On 1/14/2020 7:31 PM, Rick C wrote:
On Tuesday, January 14, 2020 at 7:31:25 PM UTC-5, amdx wrote:

Before you get to flippant with your comments, this was my very first post.

" My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat."
I'm done.
Mikek

I don't know why you are ticked. It has been mentioned many times that the aux heat may kick in for several different reasons. That is not my concern and it never has been. I'm not trying to reverse engineer the thermostat. It has never been about that as I've said any number of times.

I just wanted to ask if anyone knew of a thermostat that properly adjusts the set temperature so as to NOT turn on the aux heat. But everyone ignores my request. From the first post, "I'm wondering if anyone makes a programmable thermostat that deals with this issue."

Anyway, seems the answer is, "No, no one knows anything about a thermostat that won't trigger the aux heat when bringing up the set temp five degrees".

Sorry you are upset. Thanks anyway.

Ok, one more, I don't know your Tou schedule so I'm just picking times.
Does your existing thermostat have enough programmable times to allow
you to say Turn on at 6am and warm the house to 64* then at 7am warm the
house to 67*, then at 8am warm the house to 70*. Might not take an hour
to warm the house 3*.

No, I covered that in another message. There are a total of four settings a day and that is needed to cover the two setback time periods each day in the winter. Off at 6AM, on again at 9AM, off at 5PM on again at 8 PM.

Or if your delta is 3* to cause aux to work, them make the difference
2*, 63*, 65*, 67*, and 69* over what ever period of time it takes to
warm the house 2* each run.
No, I don't know of a thermostat that will solve you problem
Mikek

If you had one temperature where you would want the Aux to run,
say 60 degrees. You could put a Mechanical 60 degree 'open on temp rise'
switch in the thermometer wire that tells the control board to turn on
the aux heat. That way the aux would never run unless the house temp was
below 60 degrees. I have no clue if that works for you because you never
gave me a good answer to, When do you want the aux heat to run?

I don't think can just turn off the aux heat with a relay. In my other house with oil heat it turns off the heat pump when running the aux heat. So when the oil burner didn't come on the house would have no heat at all! Maybe this house does or doesn't do that, I can't say. But I'm not really looking for such an invasive solution. I'd have to tap into the wires from the thermostat inside the furnace and I'm not keen on doing something like that.

Someone I know had a furnace installed and they had to return at some point to repair something. The next day the furnace caught fire and the house burned down. I don't want anyone pointing fingers at my invasive approach if something happened. I say that, but I did install my own humidifier. Not much difference except it doesn't connect to the furnace wiring. They actually use a pressure switch to sense the differential pressure between the plenum and the cold air return. The first one was bad and being an aftermarket kit, they sent me a whole other kit!!! lol

I'm ready to drop this. It's only an issue on the colder days and it's just the one hour when it has to come up to temperature. My utility provides consumption data by the hour and alerts. I have it set for an alert when hourly consumption is over 10 kWh. Unless the aux heat runs the whole hour it's hard to get that high.

It looks like it is not uncommon to use about a dollars worth (12 kWh) of electricity in those hours, but not every time for sure. It is hard to tell if this is more electricity than it would have used in the off period as the usage is often well below a third of this prior to the off period. The usage seems to be very uneven at best, so it's hard to speculate.

I am sure this is saving money for both me and the utility though. By not using the electricity during the peak times the rates are lower by 5x in the winter and 10x in the summer. The utility can sometimes pay an equally large peak rate in the summer. The marginal electric rates can be HUGE!

Given that the temperature doesn't dip so much when the system is off, it would definitely be practical for most to be on ToU and cut their heat at those times. I house I'm looking at buying is a very old stone structure built before the battle of Gettysburg. When the price of oil went up to $4 a gal, they installed straight electric heaters with bricks inside. The bricks keep enough heat that the utility cuts off the heat at peak times and they charge a much lower rate. It ends up being pretty practical.

I want the aux heat to run when the house can't be kept warm by the heat pump alone. That has little to do with the problem with the setback returning to the normal temperature.

--

Rick C.

-++- Get 1,000 miles of free Supercharging
-++- Tesla referral code - https://ts.la/richard11209

 

[Whoey Louie]

On Wednesday, January 15, 2020 at 12:16:52 AM UTC-5, Rick C wrote:

On Tuesday, January 14, 2020 at 9:28:55 PM UTC-5, amdx wrote:
On 1/14/2020 7:31 PM, Rick C wrote:
On Tuesday, January 14, 2020 at 7:31:25 PM UTC-5, amdx wrote:

Before you get to flippant with your comments, this was my very first post.

" My thinking is, the thermostat sees a high delta between the house
temperature and the set temperature. In order to correct that (for your
comfort) it turns on both heat pump and auxiliary heat."
I'm done.
Mikek

I don't know why you are ticked. It has been mentioned many times that the aux heat may kick in for several different reasons. That is not my concern and it never has been. I'm not trying to reverse engineer the thermostat. It has never been about that as I've said any number of times.

I just wanted to ask if anyone knew of a thermostat that properly adjusts the set temperature so as to NOT turn on the aux heat. But everyone ignores my request. From the first post, "I'm wondering if anyone makes a programmable thermostat that deals with this issue."

Anyway, seems the answer is, "No, no one knows anything about a thermostat that won't trigger the aux heat when bringing up the set temp five degrees".

Sorry you are upset. Thanks anyway.

Ok, one more, I don't know your Tou schedule so I'm just picking times.
Does your existing thermostat have enough programmable times to allow
you to say Turn on at 6am and warm the house to 64* then at 7am warm the
house to 67*, then at 8am warm the house to 70*. Might not take an hour
to warm the house 3*.

No, I covered that in another message. There are a total of four settings a day and that is needed to cover the two setback time periods each day in the winter. Off at 6AM, on again at 9AM, off at 5PM on again at 8 PM.

Simple solution, don't bother setting it back. How many days a year does
a house with a heat pump system drop enough in just 3 hours to make it
worthwhile to set it back? Heat pumps, at least air based ones which
are 99% of the ones out there, are typically in moderate climates.
If it's 25F outside and I turn off my furnace, it only drops maybe 2 deg
in 3 hours. Not much point. All you're saving is the heat loss due to the
house being at 68F instead of 70F. So over 3 hours, the average is 69F.
The heat loss is largely a function of the temp difference. So with the
temp at 70F, your delta is 70-25out = 45. With it averaging one degree
lower, you're at 69-25 = 44 delta. Very little difference. If you set it
back for eight hours overnight, then you could see it drop 6 deg,
averaging 3 deg for 8 hours which is more significant. And if you're somewhere
that it's cold much of the time, an air heat pump isn't a good solution.
I've said before that from what I've seen, most heat pump systems are
not set back, even overnight because if you do so, to get it warmed
up again in the morning frequently requires aux electric heat and
that costs a lot of money.

Or if your delta is 3* to cause aux to work, them make the difference
2*, 63*, 65*, 67*, and 69* over what ever period of time it takes to
warm the house 2* each run.
No, I don't know of a thermostat that will solve you problem
Mikek

If you had one temperature where you would want the Aux to run,
say 60 degrees. You could put a Mechanical 60 degree 'open on temp rise'
switch in the thermometer wire that tells the control board to turn on
the aux heat. That way the aux would never run unless the house temp was
below 60 degrees. I have no clue if that works for you because you never
gave me a good answer to, When do you want the aux heat to run?

I don't think can just turn off the aux heat with a relay.

Yeah, you keep saying that, coming up with all kinds of bizarre claims,
like house electric service could not support aux heat and the heat
pump at the same time, but all the evidence, like the manual
for your thermostat says otherwise. You could just turn it off
with a switch.





> In my other house with oil heat it turns off the heat pump when running the aux heat.

It's also possible that some incompetent installer didn't know WTF they
were doing. Would not be the first time. I mean it's incredibly stupid
to turn off the heat pump, unless it's too cold outside. Turning it off
does two things:

1 - Greatly increases the amount of time to raise the temp

2 - Substitutes using electric energy with resistance heat for all the
heating, instead of the heat pump which gets 4X more heat for the same $$.
Or using fuel oil, which is probably more expensive too, if it's oil.

So when the oil burner didn't come on the house would have no heat at all! Maybe this house does or doesn't do that, I can't say.

Geez, you never turned the heat up several degrees and noticed what happens?
Just turn it up 5 deg, that will trigger aux heat. Then either the compressor
is running and making noise or it's not.

Also, your thermostat is obviously made by Honeywell, it looks like and
the programming is the same as their VisionPro series. The VP series
has an INDICATOR on the display, which shows when aux heat is turned on.
If Trane hosed you and yours doesn't and you have a common connection
at the thermostat, you can easily put an led on it to see what's going on.



> But I'm not really looking for such an invasive solution. I'd have to tap into the wires from the thermostat inside the furnace and I'm not keen on doing something like that.

Nonsense. The thermostat calls for heat, it calls for aux heat. RTFM

Someone I know had a furnace installed and they had to return at some point to repair something. The next day the furnace caught fire and the house burned down. I don't want anyone pointing fingers at my invasive approach if something happened.

Yeah, figured that was coming. Just give up and call the Trane service
people.




I say that, but I did install my own humidifier. Not much difference except it doesn't connect to the furnace wiring. They actually use a pressure switch to sense the differential pressure between the plenum and the cold air return. The first one was bad and being an aftermarket kit, they sent me a whole other kit!!! lol

I'm ready to drop this. It's only an issue on the colder days and it's just the one hour when it has to come up to temperature. My utility provides consumption data by the hour and alerts. I have it set for an alert when hourly consumption is over 10 kWh. Unless the aux heat runs the whole hour it's hard to get that high.

It looks like it is not uncommon to use about a dollars worth (12 kWh) of electricity in those hours, but not every time for sure. It is hard to tell if this is more electricity than it would have used in the off period as the usage is often well below a third of this prior to the off period. The usage seems to be very uneven at best, so it's hard to speculate.

I am sure this is saving money for both me and the utility though. By not using the electricity during the peak times the rates are lower by 5x in the winter and 10x in the summer. The utility can sometimes pay an equally large peak rate in the summer. The marginal electric rates can be HUGE!

Given that the temperature doesn't dip so much when the system is off,

Well, duh! Exactly what I said above. Then there is little point to setting
it back to begin with.





it would definitely be practical for most to be on ToU and cut their heat at those times. I house I'm looking at buying is a very old stone structure built before the battle of Gettysburg. When the price of oil went up to $4 a gal, they installed straight electric heaters with bricks inside. The bricks keep enough heat that the utility cuts off the heat at peak times and they charge a much lower rate. It ends up being pretty practical.

I want the aux heat to run when the house can't be kept warm by the heat pump alone. That has little to do with the problem with the setback returning to the normal temperature.

--

It has everything to do with returning back to the normal temperature,
because that is what triggers the aux heat that you're complaining about.
It will invoke aux heat under two conditions:

1 - It can't maintain the set temp with just the heat pump because it's
too cold outside or so cold that the heat pump is locked out.

2 - The set temp is raised more than a couple degrees, so it turns it on
to get you to the new temp quicker than without aux heat.

Your problems is #2. When you set it back, you introduce the possibility
of #2, if the temp drops more than one or two degrees.


Also, your thermostat has program variable #0680, which sets how aggressive
it manages heat mode.


'Applies to recovery ramp and use of auxiliary heat during recovery.

1—less aggressive
temperature control (could
cause temperature
undershoot)

2 -standard

3—more aggressive
temperature control (could
cause temperature overshoot)

They don't spell it out beyond that, but it sounds like if you selected
1, it might not be as aggressive turning on aux heat. Easy to try.

But heh, better to rant about what can't be done.