# water tempering tank above wood stove



## Jerry in MN (Dec 2, 2007)

From thread re. water heater temp.:


Windy in Kansas said:


> If the water coming into the home is quite cold an uninsulated tempering tank might be beneficial if it can gain a few degrees of heat from the air in a basement or such.


I like the idea of a tempering tank. The water coming in here is quite cold, very likely between 35 and 40 deg F this time of year. And I'd like to warm it up even more before it goes to the water heater. So I'm rounding up parts to put a tempering tank in my basement above my wood stove. The tank would go inside of a vertical air duct that would be about 2' wide by 4' deep. This duct would feed into existing ductwork. The tank would probably be set up from the stove by at least a few inches to minimize risk of overheating. I'm thinking about a 30-50 gallon tank would be about the right size. From there the water would still go through my electric water heater too.
Any recommendations on what type of tank to get? Would galvanized be OK or would it have to be stainless, or other options? Any other ideas or suggestions? Thanks!


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## Jim-mi (May 15, 2002)

Galv just fine

Don't just talk about it
Do it
Are you done yet ?
post some pix


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## Jerry in MN (Dec 2, 2007)

Gotta get the tank first. Got the copper already. And I've gotta move the water heater closer to the stove too.


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## bentbldr (Apr 25, 2007)

I did something like this in a fishing camp. I used a plastic tank set to one side and took a coil of 1/2" copper tubing and wrapped it around the stove pipe. I got about 20deg rise in water temperature with this. Since the cabin was not continuously occupied, we drained the tubing when we shut the cabin down.


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## raymilosh (Jan 12, 2005)

I recommend either finding a dead water heater and using the tank or if you want to be assured it will last for many years, buy a new water heater and using that tank. Some are steel, some are glass lined steel. They're all pretty reliable, some are better insulated than others.


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## WisJim (Jan 14, 2004)

For the tempering tank, just use a water heater tank and take the insulation off so it will pick up room heat quicker. I see lots of water heaters in the local shopper paper, some of them almost brand new. Many are LP (propane) that people are replacing with Natural gas units. You don't car, you just want a tank that is not leaking and is okay for potable water.


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## Al. Countryboy (Oct 2, 2004)

We have an insulated hot water heater sitting beside our chimney with a pipe running into the inside of chimney from the bottom of the heater. It goes up inside the chimney where all the heat from the wood burning heater goes out and runs up about 4 ft. and back out into the top of the water heater.This water circulates getting hotter and hotter before it goes into our electric hot water heater on the other side of the chimney. Not sure of the temp. of the water in the holding tank, but do know that the pipe leaving it feels warm to the touch when leaving to the electric water heater. I feel that there are many days that the electric heater rarely kicks on which off sets the use of electricity that the wood heater uses to circulate the warm air through our home.


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## fishhead (Jul 19, 2006)

If you were closer I'd give you an old water heater tank that I have sitting in my basement.


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## MELOC (Sep 26, 2005)

fishhead said:


> If you were closer I'd give you an old water heater tank that I have sitting in my basement.



if you were closer, i would race him to get it, lol.


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## greg273 (Aug 5, 2003)

I am working on something similar, a water pre-heater using the woodstove, using a tank above the stove and a thermosiphon loop.
The old electric water heater tank I was going to use has a plastic-lined foam insulation surrounding the tank. I think it needs to go. The tank will sit less than 2 feet from the stove, I am seriously concerned the plastic will melt. The old-style water heaters with the fiberglass insulation would be better, but finding one of those in decent shape is just about impossible!
I would really like to have the benefits of the insulated tank, I guess I will have to strip the jacket off the tank and replace the foam/plastic with fiberglass, or just go with the uninsulated tank. Ah, descisions descisions.


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## Jerry in MN (Dec 2, 2007)

greg273 said:


> I guess I will have to strip the jacket off the tank and replace the foam/plastic with fiberglass, or just go with the uninsulated tank.


FWIW...I intend to use an uninsulated tank. Seems the tank and water in it would have a buffering effect on the temperature of the air in the duct, in other words, they would be thermal mass.


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## fishhead (Jul 19, 2006)

MELOC said:


> if you were closer, i would race him to get it, lol.


Check your local scrap/recycling yard. You could find 100 tanks in our area.


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## Al. Countryboy (Oct 2, 2004)

While rigging up the system that was used to head water by using our heat in the chimney I went to a scrap metal place and bought an old tank, but after taking all the styrofoam insulation from around it I found that it had a number of small leeks. I think that most of the tanks that you will find in these type places have rusted out tanks.


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## greg273 (Aug 5, 2003)

OK, I AM ripping out all the foam/plasitc insulation from this tank and using it in its 'uninsulated' state. I gave it a 'test run' this weekend. Hoisted it up on my custom-made stand i spent all saturday building, fired up the woodstove and was alarmed, but not surprised, at the high temperatures on the metal shell of the tank... and that plastic wrapped foam is touching that, so, as I suspected, the plastic needs to go!

Well, go with your instincts/logic on this stuff, I guess. Plastic has NO PLACE being anywhere NEAR a woodburner!


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## greg273 (Aug 5, 2003)

the foam comes off pretty easily, had to put the tank on a tarp and use a scraper, took less than ten minutes. Built a brush fire to clean off the glue residue, (ok, not enviormentally friendly) and now will wire-brush the tank.

I love having days off from work, I get to work around the house! (And sit at the computer and drink coffee,and argue with the people in GC  )


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## CurlyHfarm (Feb 1, 2007)

I was thinking of doing something like that also. My hot water tank and wood stove are about 10 feet apart, the room that the wood stove is in is about 80-85* when we have the fire cranked up. I was goign to run flexable pex pipe back and forth along the wall behind the stove and right into the H2O tank I think that we could use about 120' of pipe. What are your thoughts about this? Another reason I did not do it yet is because I could not find any data about how much power I would save it I "pre heated" the water"


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