Water heating using ONLY the pilot light

[dremd]

Originally Posted by dremd

I'm still impressed that the water will stay/ get warm.

Quoting myself because I have seen it work.
I turned my grandmothers natural gas water heater to pilot only wile she was away for 3 months. Every time I checked on her house I ran some hot water and every time it burnt me (slightly). no added insulation, or vent modifications.

Still loving my solar + tankless setup though.

[Frank Lee]

Perhaps "newer" gas water heaters have more efficient pilots?

Mine is 20 years old, I installed a store-bought tank blanket, and on pilot only nope, no way, is the water hot enough. This from a guy that heats his house to 48 degrees.

I did the same thing with the water heater as I did with the thermostat: lowered it until it failed to live up to a minimal standard. And I do mean minimal. The water heater ended up at the "vacation" setting for me. My guess is, it fires up about once/day... right AFTER I shower I would like for it to do that just prior to shower time and have thought about putting a lever on the control knob, limit the lever's range and spring load it to the low limit, and run a string up to the bathroom that can be tugged, oh, 10 min prior to shower time.

[Christ]

My Father's got an electric water heater that runs for 1 hour once a day, on a timer. It ran at noon yesterday, and still had hot water when I left at 1AM this morning. There is no tank blanket or anything... it's just a normal water heater. I think that's pretty good, especially considering that it's on a concrete floor in the root cellar/back room area, which isn't heated.

I find that pretty impressive.

[Christ]

Where would one find specs for the flow/burn rate of the pilot lights of various heater brands/models?

This information could clarify why it seems like some machines can do this well, while others can not.

Also - is it safe to leave a propane heater unvented indoors? Propane is supposed to burn 99% efficiently, and what about ventless heaters? They burn far more fuel than a water tank, surely, and they're not vented at all.

[probsolver]

Originally Posted by Frank Lee

I installed a store-bought tank blanket, and on pilot only nope, no way, is the water hot enough. .

Just buying a water heater "blanket" will usually NOT be enough. We all should know that most heat is lost on top ( we are always told to put heaviest insulation in our attic), therefore the biggest change has to be the top of your tank. It is the presence of the vent (that is only needed when heater burner kicks on) that makes fully insulating the top impossible if not at least impracticle. If you go to "pilot only", you don't need the 3" vent and therefore can heavily insulate the top of your tank. I would also put at least R19 batting of Owens Pink around the whole tank, leaving only the bottom near the pilot open. If you are conserned about the small amount of emmissions from the pilot, it is still far better to leave a 1/4" hole for that than a 3" hole for the full burn emmissions. A roll of insulation is cheap and could be recovered in 1 to 2 months of pilot only heating.

Please try "SUPER-INSULATING" your tank and then post again with your new findings. That will be important info for all of us to see.

[probsolver]

Well, sort of. If you are on a public nat. gas line then you simply measure your consumption during a month when your furnace is not running. If you have multiple appliances, you can get a general idea by dividing usage by the number of pilots burning. Before going offgrid on gas, I found that I was billed $4 per month for my pilot. Problem is, I can't swear for sure if I had turned my furnace pilot off at that time.
You also have to consider that some pilots are single flame and some of the newer that still use pilots have two.
Sure the newest high efficiency heaters don't have them, but lets help the millions of people who don't have one and can't adfford to get one yet!

One last thing: Your pilot may use $4 / month, and your heater may use $15 / month if allowed to kick on . . . but your provider may be charging you $10 to $20 per month just to be connected to the system. I saved $240 a year simply by breaking away from my natural gas supplier. This was the service charge I got even if I didn't use any gas. That gives me some money to invest in alternative methods of heating space and water above and beyond the actual cost and impact of burning the fuel.

[NiHaoMike]

If you're using so little that the fixed service fee is excessive, it might be a good idea to switch to propane. You'll need to readjust the burners since less propane is needed for a stoichiometric burn.

[OffGridKindaGuy]

Hi.. I'm the guy with the pilot only set up. 12vman.com

My system works well because the input water temperature is around room temperature. I store my water in my living space during the winter so it doesn't freeze up.

If you were to pull water in from water lines in the ground, the input temperature would be about 52 degrees. It would take days for the tank to recover to a comfortable, usable temperature.

Gary did some calculations on how much energy my idea would use..

~Don

[Christ]

Originally Posted by OffGridKindaGuy

Hi.. I'm the guy with the pilot only set up. 12vman.com

My system works well because the input water temperature is around room temperature. I store my water in my living space during the winter so it doesn't freeze up.

If you were to pull water in from water lines in the ground, the input temperature would be about 52 degrees. It would take days for the tank to recover to a comfortable, usable temperature.

Gary did some calculations on how much energy my idea would use..

~Don

Nice to meet you, and good first post here. Welcome to EM!

Question - What effect do you think a solar pre-heater would have to using ground water in this setup? A smallish one, not one that's sufficient to heat the water for the home.

[probsolver]

Hey 12vman, awesome job putting some calculations from Gary in. Builditsolar is a great resource!!
If you use his calculations, and super-insulate your tank (we're not talking about an attic here), you could heat 30 gallons from 52 to 120 at only 82% efficiency.
Insulation (heavy) is the key and made possible only after and because the vent on top is no longer used.

And yes to the next post . . . any simple solar pre-heater would go along way just as 12vman mentioned because it takes less energy to heat wamr water than it does to heat cold.
You don't have to mortgage the house to make an improvement, or make a difference.