OT -- Tankless water heaters

[The Real Bev]

I ask here because the home repair group is worthless and you guys are
smart.

Anybody see a downside to a natural-gas tankless water heater? We don't
need a huge quantity of hot water at any one time and the tankless ones
seem cheaper than the normal ones which eventually solidify with SoCal
hard-water crap.

--
Cheers, Bev
"Tell someone you love them today, because life is short.
But scream it at them in Klingon, because life is also
terrifying and confusing." -- D. Moore

 

While I don't have gas, I can relate my own experience with tankless systems (oil in this case).

I recently (3 years ago) replaced an old (26 year) furnace that was tankless for hot water. I now have a more efficient system with a separate hot water tank. The tank looks like a heating zone to the furnace. The difference here is that the furnace now holds about 1 gallon of water in it. The old one had 2.5 or more. Since the heat exchanger resides on the top of the furnace, the exhaust passes it as well. This means that when not running, the heat continues to go up the chimney. This in turn makes each call for water to require to heat up the internal water as well as what is used.

Now, the hot water is in a large tank (like a thermos bottle) that doesnot lose heat (at least not much). With no change in use (I heat with wood so this is only used for hot water), I have reduced my oil consumption by 80%.
The furnace may run periodically to keep the water hot, but only when it is called for.

The oil company hates me now. Even with heating with wood, I would fill the tank multiple times per year. In the last 3 years, I have used less than 300 gal of oil per year down from over 1200-1600. At this rate, the new furnace will be paid from savings by the end of next year, a 4.5 year payback.

I would recommend using a separate hot water tank for the most savings.

Dan

 

[pfjw@aol.com]

On Friday, September 28, 2018 at 3:15:41 PM UTC-4, The Real Bev wrote:

Anybody see a downside to a natural-gas tankless water heater? We don't
need a huge quantity of hot water at any one time and the tankless ones
seem cheaper than the normal ones which eventually solidify with SoCal
hard-water crap.

I will give you two perspectives:

a) At our summer house, we have a Bosch instant-hot LP-fired water heater. It has been in place now for over 10 years and is flawless. It makes infinite hot water for a small house - one full bath, kitchen and outside shower. It is fed from a shallow well, again with no issues at all.

Upside: NO storage of hot water. 90%+ efficient.
Downside: There is a definite threshold before the flame starts, so those who dribble-rinse their dishes will be unhappy. And turning the water on and off leaves a (small) gap of cold water with each flame-start.

At the main house, we have a Weil-Mclain Ultra boiler with an indirect storage tank (40 gallons) that is super-insulated. As the boiler is 230,000 BTU, it can more than keep up with any demand, but the storage maintains a precisely even temperature irrespective of demand and incoming temperature. The boiler is 96% efficient, and we heat a 5,000 s.f. 1890-vintage center-hall colonial with no difficulty at all.

I would never go back to a conventional storage water heater, again.

Peter Wieck
Melrose Park, PA

 

I've only seen gas ones. Actually I saw one advertised for about $ 250 which I think is reasonable if it is reliable.

From what I recollect you need a 1" gas line to it, and on top of flue (which is cool enough to use PVC I think)you need a fresh air intake otherwise whenever it runs it creates a sight vacuum pulling in air that is not heated nor cooled to your satisfaction. The next one here might be a tankless, we got a 1½" gas line right near the existing tank.

I don't know about electric ones, but common sense tells that they pull alot of juice. You might actually need to upgrade your service unless it is already new enough. No flue or intake though, which you would need not just for gas, but for LP, propane, anything that burns.

If you install it yourself, fuck all that noise about a pipe threader, get the precut, threaded gas (sometimes called "black") pipe and then the unit goes where it goes and you adjust the water lines to accomodate. Almost anything is easier to deal with than thickwall 1" steel pipe.

If the existing tank here goes I will know alot more because we do not call contractors, well except for roofing and concrete and not all the time for that either. The houses of almost everyone we know are worked on by me, or Jack if he gets back into it.

 

[The Real Bev]

On 09/28/2018 04:21 PM, jurb6006@gmail.com wrote:

I've only seen gas ones. Actually I saw one advertised for about $
250 which I think is reasonable if it is reliable.

From what I recollect you need a 1" gas line to it, and on top of
flue (which is cool enough to use PVC I think)you need a fresh air
intake otherwise whenever it runs it creates a sight vacuum pulling
in air that is not heated nor cooled to your satisfaction. The next
one here might be a tankless, we got a 1½" gas line right near the
existing tank.

OK, you guys have convinced me that they're OK.

Our tank-heater refuses to light, and we've had it long enough that it's
probably been reduced to half the original volume. Google has
igniter-changing videos, but that looks painful for people who don't
like kneeling/lying on the floor. The gas company guy is coming Monday
to take a look, and I assume he can tell us what additional stuff we
might need and maybe roughly how much it will cost to have one installed.

I do dishes maybe once a week, and I'm pretty tolerant.

I just looked at our gas bill. The gas costs $12/month (13 therms),
there's a per-house charge of $5 and $3 in taxes. I don't think we'll
break even with the savings in our lifetime, but it's worth something
to not have to deal with the tanks ever again.

--
Cheers, Bev
"Usenet is like a herd of performing elephants with diarrhea:
massive, difficult to redirect, awe-inspiring, entertaining,
and a source of mind-boggling amounts of excrement when you
least expect it." --Gene Spafford (1992)

 

[John Robertson]

On 2018/09/28 8:44 PM, The Real Bev wrote:

On 09/28/2018 04:21 PM, jurb6006@gmail.com wrote:
I've only seen gas ones. Actually I saw one advertised for about $
250 which I think is reasonable if it is reliable.

From what I recollect you need a 1" gas line to it, and on top of
flue (which is cool enough to use PVC I think)you need a fresh air
intake otherwise whenever it runs it creates a sight vacuum pulling
in air that is not heated nor cooled to your satisfaction. The next
one here might be a tankless, we got a 1½" gas line right near the
existing tank.

OK, you guys have convinced me that they're OK.

Our tank-heater refuses to light, and we've had it long enough that it's
probably been reduced to half the original volume.  Google has
igniter-changing videos, but that looks painful for people who don't
like kneeling/lying on the floor.  The gas company guy is coming Monday
to take a look, and I assume he can tell us what additional stuff we
might need and maybe roughly  how much it will cost to have one installed.

I do dishes maybe once a week, and I'm pretty tolerant.

I just looked at our gas bill.  The gas costs $12/month (13 therms),
there's a per-house charge of $5 and $3 in taxes.  I don't think we'll
break even with the savings  in our lifetime, but it's worth something
to not have to deal with the tanks ever again.

Hot water tanks typically corrode out in ten years, so if yours is
anywhere near that age it is best to replace it if it has already
stopped working. If still working put a water leakage detector under it
and keep the batteries fresh!

Go with a good name brand tankless that has a reputation for good
support, and find out how resistant to corrosion it is, this would be my
primary concern.

John :-#)#
--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[Jerry Peters]

John Robertson <spam@flippers.com> wrote:

On 2018/09/28 8:44 PM, The Real Bev wrote:
On 09/28/2018 04:21 PM, jurb6006@gmail.com wrote:
I've only seen gas ones. Actually I saw one advertised for about $
250 which I think is reasonable if it is reliable.

From what I recollect you need a 1" gas line to it, and on top of
flue (which is cool enough to use PVC I think)you need a fresh air
intake otherwise whenever it runs it creates a sight vacuum pulling
in air that is not heated nor cooled to your satisfaction. The next
one here might be a tankless, we got a 1˝" gas line right near the
existing tank.

OK, you guys have convinced me that they're OK.

Our tank-heater refuses to light, and we've had it long enough that it's
probably been reduced to half the original volume.  Google has
igniter-changing videos, but that looks painful for people who don't
like kneeling/lying on the floor.  The gas company guy is coming Monday
to take a look, and I assume he can tell us what additional stuff we
might need and maybe roughly  how much it will cost to have one installed.

I do dishes maybe once a week, and I'm pretty tolerant.

I just looked at our gas bill.  The gas costs $12/month (13 therms),
there's a per-house charge of $5 and $3 in taxes.  I don't think we'll
break even with the savings  in our lifetime, but it's worth something
to not have to deal with the tanks ever again.


Hot water tanks typically corrode out in ten years, so if yours is
anywhere near that age it is best to replace it if it has already
stopped working. If still working put a water leakage detector under it
and keep the batteries fresh!

Go with a good name brand tankless that has a reputation for good
support, and find out how resistant to corrosion it is, this would be my
primary concern.

This is important! Ask This Old House had a segment where Richard
replaced an old tankles with a new one because the manufacterer had
gone out of business leaving the old wh un-repairable.

John :-#)#

 

[Stephen Wolstenholme]

On Sat, 29 Sep 2018 10:06:40 -0700, John Robertson <spam@flippers.com>
wrote:

Hot water tanks typically corrode out in ten years, so if yours is
anywhere near that age it is best to replace it if it has already
stopped working. If still working put a water leakage detector under it
and keep the batteries fresh!

The first house I bought had a copper hot water tank that was
installed when the house was built in 1911. It had never been
replaced.

Go with a good name brand tankless that has a reputation for good
support, and find out how resistant to corrosion it is, this would be my
primary concern.

I now have a house with a Combi gas boiler that has no tank. The water
gets heated on demand. The it takes about five seconds to heat the
water.

Steve

--
http://www.npsnn.com

 

[Lee]

On 28/09/2018 20:15, The Real Bev wrote:

I ask here because the home repair group is worthless and you guys are
smart.

Anybody see a downside to a natural-gas tankless water heater?  We don't
need a huge quantity of hot water at any one time and the tankless ones
seem cheaper than the normal ones which eventually solidify with SoCal
hard-water crap.

Surprised no one has yet pointed out that if the water is that hard then
you will need to choose a model with a Teflon coated (or similar) heat
exchanger or it too will scale up eventually.

 

[Ralph Mowery]

In article <polukp$g9$1@dont-email.me>, bashley101@gmail.com says...

I ask here because the home repair group is worthless and you guys are
smart.

Anybody see a downside to a natural-gas tankless water heater? We don't
need a huge quantity of hot water at any one time and the tankless ones
seem cheaper than the normal ones which eventually solidify with SoCal
hard-water crap.

Being in SoCal may be somewhat different from other parts of the
country.

Check the price of doing all the piping to get the gas to the water
heater. It takes lots of gas for a short period of time instead of
small ammounts for longer time.

Check how long the different ones last and how much they cost and if you
can replace them yourself or need a pro to do it.

 

"It takes lots of gas for a short period of time instead of
small ammounts for longer time. "

They want a 1" gas line all the way to the meter.

"Check how long the different ones last and how much they cost and if you
can replace them yourself or need a pro to do it. "

That's a biggie these days when many people don't know how to change a flat tire. Anything with gas make sure you know what you're doing or you might go out in the proverbial blaze of glory.

Most cities will tell you you need a licensed pro and a permit, but that is incorrect. Still, if you do it yourself you can have it inspected, most places. But if in Kalifornia laws mean nothing. Liberal whims rule. So basically if you decide to do it on your own, don't even talk to them. Don't get into that legal battle. I am not afraid of it but I won't send anyone else in for that. Just keep your mouth shut about it.

If you are incapable of doing it, the best bet is to find the local plumber's union hall and find one who is in between jobs. You'll pay their rate of course, but you won't have to also pay a guy in an expensive suit to sit on his ass.

 

[The Real Bev]

On 09/30/2018 04:59 PM, jurb6006@gmail.com wrote:

"It takes lots of gas for a short period of time instead of
small ammounts for longer time. "

They want a 1" gas line all the way to the meter.

That is probably the biggest problem and the thing that kills the project.

"Check how long the different ones last and how much they cost and
if you can replace them yourself or need a pro to do it. "

That's a biggie these days when many people don't know how to change
a flat tire. Anything with gas make sure you know what you're doing
or you might go out in the proverbial blaze of glory.

We've installed 2 tankful gas water heaters before.

Most cities will tell you you need a licensed pro and a permit, but
that is incorrect. Still, if you do it yourself you can have it
inspected, most places. But if in Kalifornia laws mean nothing.
Liberal whims rule. So basically if you decide to do it on your own,
don't even talk to them. Don't get into that legal battle. I am not
afraid of it but I won't send anyone else in for that. Just keep
your mouth shut about it.

If you are incapable of doing it, the best bet is to find the local
plumber's union hall and find one who is in between jobs. You'll pay
their rate of course, but you won't have to also pay a guy in an
expensive suit to sit on his ass.

We'll see. Maybe it's just a simple thing -- the water heater
equivalent of banging on the side with a wrench. All pigs fed and ready
to fly.

--
Cheers, Bev
"Screw the end users. If they want good software,
let them write it themselves." -- Anon.

 

[pfjw@aol.com]

On the 1" line to the meter - it ain't necessarily so. The size of the line is dependent on the size of the heater, the distance from the meter, and the gas pressure. Keep in mind that the typical tankless heater uses somewhere between 150,000 BTUH and 250,000 BTUH.

One cubic foot of gas is 1,010 BTU - use 1,000.

You will need between 150 and 250 cubic feet of gas per hour. That is 2.5 - 4.2 cf/minute.

https://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_826.html Will help you size the needed pipe.

There is also flexible piping these days that is a breeze to install (unless you are a expert, amend that a breeze for *someone else* to install), and around here, the gas utility will do a certain amount of internal work if you are installing a new appliance.

If the only gas you burn is to make hot water, you are absolutely correct that the payback will be beyond your expected lifetime. In a full-time residence, storage-losses are insignificant, use is constant, and the relative difference in installed cost between an instant and a conventional tank-storage heater (3:1) blows up the financial advantages. For our summer house, the use patterns are quite different, the house is at the end of a long dirt 'lane', making propane delivery inconvenient (we get an annual delivery along with a tank inspection), so reducing use and storage losses is important. That a tankless is +/- 28% more efficient than even the best storage-type heaters, and takes up almost no space are additional advantages applicable in a small summer house.

Peter Wieck
Melrose Park, PA

 

[The Real Bev]

Top-posting as a notification that we dodged the bullet this time -- we
just couldn't actually see the pilot flame because it required lying on
the floor and looking up OR using a mirror to do it like the gas company
guy did.

Onward and upward and thanks to all you guys for your help.


On 10/01/2018 05:02 AM, pfjw@aol.com wrote:

On the 1" line to the meter - it ain't necessarily so. The size of
the line is dependent on the size of the heater, the distance from
the meter, and the gas pressure. Keep in mind that the typical
tankless heater uses somewhere between 150,000 BTUH and 250,000
BTUH.

One cubic foot of gas is 1,010 BTU - use 1,000.

You will need between 150 and 250 cubic feet of gas per hour. That is
2.5 - 4.2 cf/minute.

https://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_826.html
Will help you size the needed pipe.

There is also flexible piping these days that is a breeze to install
(unless you are a expert, amend that a breeze for *someone else* to
install), and around here, the gas utility will do a certain amount
of internal work if you are installing a new appliance.

If the only gas you burn is to make hot water, you are absolutely
correct that the payback will be beyond your expected lifetime. In a
full-time residence, storage-losses are insignificant, use is
constant, and the relative difference in installed cost between an
instant and a conventional tank-storage heater (3:1) blows up the
financial advantages. For our summer house, the use patterns are
quite different, the house is at the end of a long dirt 'lane',
making propane delivery inconvenient (we get an annual delivery along
with a tank inspection), so reducing use and storage losses is
important. That a tankless is +/- 28% more efficient than even the
best storage-type heaters, and takes up almost no space are
additional advantages applicable in a small summer house.

Peter Wieck Melrose Park, PA

--
Cheers, Bev
An organizer for the "Million Agoraphobics March" expressed
disappointment in the turnout for last weekend's event.

 

[John Robertson]

On 2018/10/01 3:06 PM, The Real Bev wrote:

Top-posting as a notification that we dodged the bullet this time -- we
just couldn't actually see the pilot flame because it required lying on
the floor and looking up OR using a mirror to do it like the gas company
guy did.

Onward and upward and thanks to all you guys for your help.

You might want to add that eventual replacement $$ into your house
savings account...

John :-#)#

On 10/01/2018 05:02 AM, pfjw@aol.com wrote:
On the 1" line to the meter - it ain't necessarily so. The size of
the line is dependent on the size of the heater, the distance from
the meter, and the gas pressure. Keep in mind that the typical
tankless heater uses somewhere between 150,000 BTUH and 250,000
BTUH.

One cubic foot of gas is 1,010 BTU - use 1,000.

You will need between 150 and 250 cubic feet of gas per hour. That is
2.5 - 4.2 cf/minute.

https://www.engineeringtoolbox.com/natural-gas-pipe-sizing-d_826.html
Will help you size the needed pipe.

There is also flexible piping these days that is a breeze to install
(unless you are a expert, amend that a breeze for *someone else* to
install), and around here, the gas utility will do a certain amount
of internal work if you are installing a new appliance.

If the only gas you burn is to make hot water, you are absolutely
correct that the payback will be beyond your expected lifetime. In a
full-time residence, storage-losses are insignificant, use is
constant, and the relative difference in installed cost between an
instant and a conventional tank-storage  heater (3:1) blows up the
financial advantages. For our summer house, the use patterns are
quite different, the house is at the end of a long dirt 'lane',
making propane delivery inconvenient (we get an annual delivery along
with a tank inspection), so reducing use and storage losses is
important.  That a tankless is +/- 28% more efficient than even the
best storage-type heaters, and takes up almost no space are
additional advantages applicable in a small summer house.

Peter Wieck Melrose Park, PA

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

On Friday, September 28, 2018 at 7:21:08 PM UTC-4, jurb...@gmail.com wrote:

I've only seen gas ones. Actually I saw one advertised for about $ 250 which I think is reasonable if it is reliable.

From what I recollect you need a 1" gas line to it, and on top of flue (which is cool enough to use PVC I think)you need a fresh air intake otherwise whenever it runs it creates a sight vacuum pulling in air that is not heated nor cooled to your satisfaction. The next one here might be a tankless, we got a 1½" gas line right near the existing tank.

I don't know about electric ones, but common sense tells that they pull alot of juice. You might actually need to upgrade your service unless it is already new enough. No flue or intake though, which you would need not just for gas, but for LP, propane, anything that burns.

If you install it yourself, fuck all that noise about a pipe threader, get the precut, threaded gas (sometimes
called "black") pipe and then the unit goes where it goes and you adjust the water lines to accomodate. Almost
anything is easier to deal with than thickwall 1" steel pipe.

Installing that might need a gas service shut-off AND an electric utility shut-out before work begins in addition to everything else. Just to make sure the random spark doesn't find its way in.

> If the existing tank here goes I will know alot more because we do not call contractors,

Then you bear future insurance costs instead of them.

 

[pfjw@aol.com]

I used flex and a flaring tool. Flare-nut fittings are reliable, simple (remember to put the nut on before making the flare!), and effective. So, black-iron to include the drip-leg, and flex to make the last 18". I have a cut-off at the tank, at the T-fitting, and at the heater itself. Power is on a wall-switch nearby.

Neat, simple and safe.

Inspected by the Propane Supplier and passed.

NOTE: Many gas cut-off valves require considerable hand strength, or have very short handles. I installed devices such that were kid and wife-tested. They do exist, usually for a couple of bucks more. They are well worth it.

Peter Wieck
Melrose Park, PA

 

>"Installing that might need a gas service shut-off AND an electric utility shut-out before work begins in addition to everything else. Just to make sure the random spark doesn't find its way in. "

This particular tank has no electricity. It is fright next to the furnace. The furnace is supposed to be all by itself but we got all conduit so I can easily pull more wire through it.

Far as the gas is concerned there is a shutoff right by the meter. Plus I know what I'm doing, not that I would work on live gas. It's bad enough when I work on live electricity. And don't start that safety shit, there are plenty of installations with shared neutrals that can kill you just as fast with the branch circuit turned off, and it is impractical to turn off the whole building. So sometimes you just have to know how to respect electricity..

>"Then you bear future insurance costs instead of them. "

Only if it is the cause of the damage. The old you are responsible for anything and everything if the place burns down is an old Husband's tale. Like driving with no license or under suspension, many people will tell you anything happens, even if you get rear ended it is your fault, that is also bullshit. If it IS your fault you may be in more hot water but if it is not your fault all is the same. Even if the cops is WRONG and puts "caused" "Accident" on there that is not a judgement and it gets thrown out of court and disappears and you get a reduced charge.

Plus the fact that nothing is going to happen. With all the work I've done and no problems I would rather do it than have anyone else do it, I have seen their work. It's like a contractor's license is to do whatever you want, and business insurance to so you don't lose your assets if you get sued. Shit should be illegal and people should be responsi9ble for what they do.

Of course people are so god damn stupid I saw an insurance card or something that said "Having insurance does not prevent you from having an accident, you must still drive safely". And you know about the notice in the newer RVs right ?

Anyway, what I meant by the heater goes where it does is because I am not getting a pipe threader that big to do one job. I mean, how many people are going to call me out of the blue to do that ? So then precut pipes go where they go and you adjust the water lines and electrical to hit where it is. I can run pipe and conduit.

Of course some people call the gas company to light a pilot light. In fact years ago a buddy was on his way up my front step and a neighbor who had just moved in pulled him aside and paid him $ 20 to install a gas stove. Just hook it up. I could understand if he knew me and looked for me, but not knowing anything... ??? And then they get % 75 to install a ceiling fan into an existing box if it is sturdy enough, which takes about a half hour. I would do it for $ 50 if it is local. If I have to travel then of course it is more. And actually it is the DIY stores that do it for $ 75, a real electrician would charge quite a bit more.

The one thing I will not do right now is install a backup generator. It has to be just right, if not you could kill a lineman. Mind you this is a guy trying to get your power back on so you don't have to keep filling the generator with whatever runs it. I haven't even seen it done so I won't.

Now, I burnt my fingers doing cement work yesterday...don't ask.

 

>"I used flex and a flaring tool. Flare-nut fittings are reliable, simple (remember to put the nut on before making the flare!), and effective."

And illegal in some areas. I heard Canada or parts of it. That means all the stoves and dryers are hard piped in. It is not that hard as long as the floor is level and solid. Obviously you have to use a union and it helps if the two sides connect.

 

>"NOTE: Many gas cut-off valves require considerable hand strength, or have very short handles."

Around here they got no handles, you need a wrench.