# Just finished...hot water from woodstove



## greg273 (Aug 5, 2003)

Well I finally got my woodstove hot water pre-heater going... heats 50 gallons of water in about 6 hours... I'l try to get some pics up here, but it is basically a 50 gallon water tank on a stand, next to the furnace, with a thermosiphon loop coiled around the chimney flue. I used 50 feet of 1/2" copper tubing for the heat collector. I've included temp and pressure gauges, so far, I've noticed NO drastic increase in system pressure. I had been very concerned about that, but it appears that any increase in pressure is taken up by the pressure tank near the cistern.
Wish I had done this years ago! And I managed to keep the cost down by using recycled material, and stuff I already had on-hand. 

Uh, can anyone tell me how to upload a photo to this thread?


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## wy_white_wolf (Oct 14, 2004)

you need to use a hosting service like photobucket and then copy and paste the <img> code into your threads. Using thread preview allows you to see what it looks like.

Impatiently waiting for pics.


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## trapperJim (Jan 24, 2008)

greg273 said:


> Uh, can anyone tell me how to upload a photo to this thread?


Yes, Just what White wolf said.

Go to www.photobucket.com and open an account - it's free.

Then follow the uploading directions to create your album. 

After you upload your pic to photobucket copy & paste the (IMG) code here. When you first paste it to your post it'll show up as code (text only) until you submit your reply. Then the pic will appear.


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## MELOC (Sep 26, 2005)

try to set the default setting to resize the pics on photobucket to something reasonable...like 800 x 600 or smaller.


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## ET1 SS (Oct 22, 2005)

greg273 said:


> Well I finally got my woodstove hot water pre-heater going... heats 50 gallons of water in about 6 hours... I'l try to get some pics up here, but it is basically a 50 gallon water tank on a stand, next to the furnace, with a thermosiphon loop coiled around the chimney flue. I used 50 feet of 1/2" copper tubing for the heat collector. I've included temp and pressure gauges, so far, I've noticed NO drastic increase in system pressure. I had been very concerned about that, but it appears that any increase in pressure is taken up by the pressure tank near the cistern.
> Wish I had done this years ago! And I managed to keep the cost down by using recycled material, and stuff I already had on-hand.
> 
> Uh, can anyone tell me how to upload a photo to this thread?


That is great!

I can't wait to see the photos.


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## greg273 (Aug 5, 2003)

My original design didnt work too well, I had the thermosiphon loop going from the bottom of the tank, going up the back of the woodstove then back into the tank. I thought that an uninsulated metal tank full of water 20" from the woodstove plus that pipe touching the firebox would be enough. Well, I guess it would be if you wanted to wait 24 hours for some lukewarm water. This new design with the coil wrapped around the flue heats up at least twenty times faster.


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## ET1 SS (Oct 22, 2005)

We have gone through changes in our design as well.

Still not entirely happy with our current system design, so this coming summer will include one more design change.

It happens.


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## mightybooboo (Feb 10, 2004)

On the PioneerMaid stove the hot water is just a section of pipe running along the back of the firebox,and does it ever put out HOT water.

Friend has it,uses thermosyphon(sp) but unsure how its actually plumbed.But boy he has plenty hot water!


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## greg273 (Aug 5, 2003)

ET1 SS said:


> We have gone through changes in our design as well.
> 
> Still not entirely happy with our current system design, so this coming summer will include one more design change.
> 
> It happens.


 Yeah, I remember looking at some pics of your setup last year sometime... you used copper coil around the flue also, if I remember correctly? What is your improvement going to consist of?
My major mistake was assuming that a few feet of 3/4 copper pipe running up the back of the firebox (on the outside) would collect enough heat. Wrong assumption. Not near enough surface area, and that is far from the hottest part of the stove. Now, with 50 feet of 1/2" tubing wrapped directly around the flue, the thermosiphon effect works great! I get at least 15 gallons of hot water per hour. Next, I want to put the insulated jacket back on the tank... I had thought, wrongly of course, that the black tank would soak up heat...well I guess it does, but way too slowly to help much. I would say 95% of the heat the tank is gaining is coming directly from the chimney coil.


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## ET1 SS (Oct 22, 2005)

greg273 said:


> Yeah, I remember looking at some pics of your setup last year sometime... you used copper coil around the flue also, if I remember correctly? What is your improvement going to consist of?
> My major mistake was assuming that a few feet of 3/4 copper pipe running up the back of the firebox (on the outside) would collect enough heat. Wrong assumption. Not near enough surface area, and that is far from the hottest part of the stove. Now, with 50 feet of 1/2" tubing wrapped directly around the flue, the thermosiphon effect works great! I get at least 15 gallons of hot water per hour. Next, I want to put the insulated jacket back on the tank... I had thought, wrongly of course, that the black tank would soak up heat...well I guess it does, but way too slowly to help much. I would say 95% of the heat the tank is gaining is coming directly from the chimney coil.


I have 50 foot of copper tubing wrapped around the outside of the upper barrel.

The upper barrel gets crazy hot, but the contact between the tubing and the barrel is not enough.

So I am going to place the tubing entirely inside of the upper barrel.


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## mightybooboo (Feb 10, 2004)

mightybooboo said:


> On the PioneerMaid stove the hot water is just a section of pipe running along the back of the firebox,and does it ever put out HOT water.
> 
> Friend has it,uses thermosyphon(sp) but unsure how its actually plumbed.But boy he has plenty hot water!


On the inside of the firebox.


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## farminghandyman (Mar 4, 2005)

still put a T&P safety relief valve on it, jsut like on a hot water heater, (temperature and pressure valve),

Evey home owner putting in there own Hot water heater should be required to watch this video. I have a video put out by Watts company and it is equally impressive and much more detailed on the why, but regardless of the why, if some thing over heats there can be danger.
[ame]http://www.youtube.com/watch?v=JmJoyuUJj2Q[/ame]

because of the pressure that is in a water system it is about the same as a pressure cap of 70+ pounds radiator cap the water can be super heated, and if or when it escapes it changes to vapor in an instant causing a explosion, so even if one has a pressure relief on the well, the water can start to vaporise and if it does it can go boom, so one want the temperature relief and pressure safety valve on the HW tank, it self, a cheap safety item,

It could save your and your family from serious harm or death,


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## ET1 SS (Oct 22, 2005)

Was anyone talking about removing a pressure relief valve?

I missed that part.


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## greg273 (Aug 5, 2003)

ET1 SS said:


> I have 50 foot of copper tubing wrapped around the outside of the upper barrel.
> 
> The upper barrel gets crazy hot, but the contact between the tubing and the barrel is not enough.
> 
> So I am going to place the tubing entirely inside of the upper barrel.


 Does your system use a pump to make the fluid move? If I recall, yours is a radiant heat setup...
I would think that if the outside of the upper barrell gets hot, 50 feet of water-filled coil would also get hot pretty quickly. I remember an old Mother Earth News story from the 70's were someone wrapped a coil around the connecting pipe between barrells... maybe the heat is more intense there? I managed to fit all 50 ft into a space about 16" tall around an 8" single-wall flue pipe. 
I'm only trying to heat 50 gallons of water, if youre using this as a radiant floor type system I guess you have a lot more mass to heat.


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## greg273 (Aug 5, 2003)

ET1 SS said:


> Was anyone talking about removing a pressure relief valve?
> 
> I missed that part.


 i hope not. A steam explosion in the house is NOT on my list of things to see anytime soon. Sounds pretty intense, I think 'Mythbusters' did a show on that, shot the hot water heater right through the roof from what I was told.


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## ET1 SS (Oct 22, 2005)

greg273 said:


> Does your system use a pump to make the fluid move? If I recall, yours is a radiant heat setup...
> I would think that if the outside of the upper barrell gets hot, 50 feet of water-filled coil would also get hot pretty quickly. I remember an old Mother Earth News story from the 70's were someone wrapped a coil around the connecting pipe between barrells... maybe the heat is more intense there? I managed to fit all 50 ft into a space about 16" tall around an 8" single-wall flue pipe.
> I'm only trying to heat 50 gallons of water, if youre using this as a radiant floor type system I guess you have a lot more mass to heat.


If you wrap tubing around the vertical stove pipe, then the water will be pushed to flow on it's own.

My tubing is wrapped around a horizontal barrel, so the water needs a pump to flow.

I have one pump to circ the floor loop and thermal bank. and a second pump to circ water through the stove and the thermal bank.


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