OT -- Tankless water heaters

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

I recently (3 years ago) replaced an old (26 year) furnace that was tankles s for hot water. I now have a more efficient system with a separate hot wa ter tank. The tank looks like a heating zone to the furnace. The differen ce here is that the furnace now holds about 1 gallon of water in it. The o ld 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 th e 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 f urnace will be paid from savings by the end of next year, a 4.5 year paybac k.

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

Dan

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 infini te 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 w ho 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 stor age 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 pre cisely even temperature irrespective of demand and incoming temperature. Th e boiler is 96% efficient, and we heat a 5,000 s.f. 1890-vintage center-hal l 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 whic h 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 (whi ch 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 heate d nor cooled to your satisfaction. The next one here might be a tankless, w

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

If you install it yourself, f*ck 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 any thing 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.

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.

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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 :-#)#

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.

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.

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.

small ammounts for longer time. "

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

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 pl aces. But if in Kalifornia laws mean nothing. Liberal whims rule. So basica lly 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 o n his ass.

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

We've installed 2 tankful gas water heaters before.

:-)

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.

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 t he gas pressure. Keep in mind that the typical tankless heater uses somewhe re 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.

There is also flexible piping these days that is a breeze to install (unles s 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 t hat the payback will be beyond your expected lifetime. In a full-time resid ence, storage-losses are insignificant, use is constant, and the relative d ifference in installed cost between an instant and a conventional tank-stor age 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 dir t 'lane', making propane delivery inconvenient (we get an annual delivery a long with a tank inspection), so reducing use and storage losses is importa nt. That a tankless is +/- 28% more efficient than even the best storage-t ype heaters, and takes up almost no space are additional advantages applica ble in a small summer house.

Peter Wieck Melrose Park, PA

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 :-#)#

he

ich I think is reasonable if it is reliable.

hich is cool enough to use PVC I think)you need a fresh air intake otherwis e whenever it runs it creates a sight vacuum pulling in air that is not hea ted nor cooled to your satisfaction. The next one here might be a tankless,

lot 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.

t the precut, threaded gas (sometimes

the water lines to accomodate. Almost

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

ll contractors,

Then you bear future insurance costs instead of them.

I used flex and a flaring tool. Flare-nut fittings are reliable, simple (re member to put the nut on before making the flare!), and effective. So, blac k-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 v ery 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

shut-out before work begins in addition to everything else. Just to make s ure 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 k now 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 pl enty of installations with shared neutrals that can kill you just as fast w ith the branch circuit turned off, and it is impractical to turn off the wh ole building. So sometimes you just have to know how to respect electricity .

Only if it is the cause of the damage. The old you are responsible for anyt hing 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 anyt hing happens, even if you get rear ended it is your fault, that is also bul lshit. If it IS your fault you may be in more hot water but if it is not yo ur fault all is the same. Even if the cops is WRONG and puts "caused" "Acci dent" 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 se en 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. S hit 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 somethin g 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 R Vs right ?

Anyway, what I meant by the heater goes where it does is because I am not g etting 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 ju st 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 kn owing 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 wo uld 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 electr ician 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 gene rator 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.

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.

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

Not much use in an emergency, then.

Peter Wieck Melrose Park, PA