Wood stove water heat

begreen · Sep 19, 2015

Squirrel said:
I'm in the process of trying a different approach.
After much searching I found a junked 20gal stainless pressure tank (from a well known soft drink company) and had a couple of pipe nipples fitted. This has been set up beside the stove in the feed to my electric water heater which is just behind the wall. Over the summer I spent a bit less heating water simply by allowing my well water to warm up to room temp. It will be interesting to see the results once the stove is running.
I know the tank would be more efficient if black but was told not to paint it and powder coating is expensive.
View attachment 161982

I put a full stainless steel flashing skirt on our house before installing the patio. I too was told don't paint it but I didn't want to have a shiny stripe sitting above the patio so I lightly sanded the 18" x 120" strips to give them tooth, wiped down with alcohol and then painted it with black Rustoleum (Universal?) metal paint. That was 10 yrs ago. It still looks great and no sign of peeling or flaking in spite of being on the south (weather and sun) side of the house.

RFarm · Sep 19, 2015

Electrathon - that is a very nice install. I am in the process of doing something similar. I am setting up a 50 gallon tempering tank that will hold the stove heated water and feed it to my 40 gallon solar heated hot water tank that resides outdoors. I got a DHW coil from my stoves manufacturer (Sedore) and plan to attach it to the outside of the stove, between the heat shield on the rear of the stove. The rear of my stove rarely gets hotter than 200 since the firebox is divided and the wood load is burned in the front chamber. I would be thrilled to get the tempering tank to 100 degrees, but really anything over 80 degrees would be a plus. I'll post pics when completed. Great post and nice job.

electrathon · Sep 19, 2015

I have never had an exposed tempering tank but did have an external coil on my stove for about a year (before the internal coil). It was located between the rear heat shield and the stove. I got very little heat out of the coil. I finally took it off and replaced it with the internal coil. My stove does not have an abundance of heat off the rear, so it could be way better on different made stoves,

Highbeam · Sep 21, 2015

Flue temps from a heritage were measured by me as nearly always between 600 and 1000 so long as the fire was up to temp and burning clean. That is the temperatures that this loop is exposed to. Should be plenty of heat to make this work. The heritage sent way too much heat up the flue that was wasted.

The outside temp of the stove is coolish but that is not what drives this water system. If the fire loop had enough surface area and was kept cold enough by circulating water it could steal too much heat. Operator skill could make or break this application of the good ol water loop system.

bwolfe1 · Nov 8, 2015

RFarm said:
Electrathon - that is a very nice install. I am in the process of doing something similar. I am setting up a 50 gallon tempering tank that will hold the stove heated water and feed it to my 40 gallon solar heated hot water tank that resides outdoors. I got a DHW coil from my stoves manufacturer (Sedore) and plan to attach it to the outside of the stove, between the heat shield on the rear of the stove. The rear of my stove rarely gets hotter than 200 since the firebox is divided and the wood load is burned in the front chamber. I would be thrilled to get the tempering tank to 100 degrees, but really anything over 80 degrees would be a plus. I'll post pics when completed. Great post and nice job.

The water coil is designed to go into the secondary burn chamber where it will easily heat 50 gallons to way over 100 degrees F. If needed an installation recommendation can be made which basically involves drilling two holes through the rear heat shield and the back wall. The cast baffle will need to be removed and the coil will slide into the rear chamber and the pipes stub out the holes that are drilled, see attached pics.

electrathon · Nov 8, 2015

Is this your own house setup or the manufactures pictures? I an curious how much coil is in the stove. How big is the pipe diameter inside the stove? Stainless coil? Are you running domestic water or anti-freeze? There was a mention of mixing the water into the solar system in the quoted post.

I am also curious about the height of the storage tank, the bottom of the tank is lower than the heat coil, in general there would be little to no circulation without a pump. Self circulating systems are based on the heat rising, the lower the tank, the less circulation.

begreen · Nov 8, 2015

Hmm, that Sedore definitely does not have the required 12" to the wall behind it. The wall appears to have no more protection than a thin tile. Also not seeing a PTR valve at the stove. Maybe one on top of the hw tank? Hopefully they're there.

WildWillie · Mar 23, 2017

begreen said:
Hmm, that Sedore definitely does not have the required 12" to the wall behind it. The wall appears to have no more protection than a thin tile. Also not seeing a PTR valve at the stove. Maybe one on top of the hw tank? Hopefully they're there.

The wall behind the Sedore is tile on top of cement board mounted to 2" steel studs, with a 2" air gap, reducing the clearance to 6"

bholler · Mar 23, 2017

WildWillie said:
The wall behind the Sedore is tile on top of cement board mounted to 2" steel studs, with a 2" air gap, reducing the clearance to 6"

Honestly I cant find anything in the manual saying you can reduce the clearance for the back wall below the stated 12" with a heat sheild. I may have missed it can you point it out for us?

WildWillie · May 1, 2017

bholler said:
Honestly I cant find anything in the manual saying you can reduce the clearance for the back wall below the stated 12" with a heat sheild. I may have missed it can you point it out for us?

Every jurisdiction, county, city, or state have the rules on clearance reductions. First contact your local fire marshall and see what theses codes/rules are? To my knowledge they always have the final say on any clearance reductions. They may also use the codes straight from NFPA. There can, and do differ everywhere. Here where I live, in the state of Minnesota, (The state that never say a law they didn't like), have chosen to have there own clearance reduction codes, which are different the the NFPA? The bottom line is that it is up to your local jurisdiction, not the stove Manufacturer.

bholler · May 1, 2017

WildWillie said:
Every jurisdiction, county, city, or state have the rules on clearance reductions. First contact your local fire marshall and see what theses codes/rules are? To my knowledge they always have the final say on any clearance reductions. They may also use the codes straight from NFPA. There can, and do differ everywhere. Here where I live, in the state of Minnesota, (The state that never say a law they didn't like), have chosen to have there own clearance reduction codes, which are different the the NFPA? The bottom line is that it is up to your local jurisdiction, not the stove Manufacturer.

No, the manufacturer determines the required clearances. Your local authority has absolutely no way to know what the required clearances are for that particular stove. Manufacturers directions override code.

bholler · May 1, 2017

And by the way I checked and minnesota has adopted the irc family of codes just like most of the country. And that code defers to manufacturers specs for any listed product.

Love the Heat · Jan 11, 2020

RFarm said:
Electrathon - that is a very nice install. I am in the process of doing something similar. I am setting up a 50 gallon tempering tank that will hold the stove heated water and feed it to my 40 gallon solar heated hot water tank that resides outdoors. I got a DHW coil from my stoves manufacturer (Sedore) and plan to attach it to the outside of the stove, between the heat shield on the rear of the stove. The rear of my stove rarely gets hotter than 200 since the firebox is divided and the wood load is burned in the front chamber. I would be thrilled to get the tempering tank to 100 degrees, but really anything over 80 degrees would be a plus. I'll post pics when completed. Great post and nice job.

Good morning Rfarm...... Have you ended-up installing the water coil??? waiting for my Sedore(Can.) to arrive and also looking at putting the coil. I've had a similar system feeding a heat exchanger from my pellet stove and planning to reuse most parts from it.. Thx in advance.

Jvd850 · Jan 23, 2024

Love the Heat said:
Good morning Rfarm...... Have you ended-up installing the water coil??? waiting for my Sedore(Can.) to arrive and also looking at putting the coil. I've had a similar system feeding a heat exchanger from my pellet stove and planning to reuse most parts from it.. Thx in advance.

Love the heat or Rfarm… What’s anyone’s experience with Sedore. It seems like it will be the best stove for my new situation. Hydronic floor heat on a slab. In the manual for the coil it says no longer than 10ft from stove to tank. Anyone have any info from their install? TIA

begreen · Jan 23, 2024

There are old threads on the Sedore. It was a downdraft stove similar to the old Tempwood. Not the cleanest burner in the world and it can be tricky to start when cold. I don't recall it ever being EPA tested.

electrathon · Jan 23, 2024

Jvd850 said:
Love the heat or Rfarm… What’s anyone’s experience with Sedore. It seems like it will be the best stove for my new situation. Hydronic floor heat on a slab. In the manual for the coil it says no longer than 10ft from stove to tank. Anyone have any info from their install? TIA

Depending on the size of your slab, you may be disappointed the your outcome. Make sure you insulate inner the slab and insulate between the slab and foundation wall. It takes a lot of BTUs to heat a floor slab, very likely way, way more than a stove coil can produce. At best you will only be able to get a couple percent of the BTUs of the stove output.

Jvd850 · Jan 24, 2024

Square footage is about 2100ft. But that includes the upstairs. It’s a newer build from 2010 and an addition in 2020. I was told it was very well insulated when poured. I see on Sedore’s website they have a coil that could do up to 60,000 BTUs. With some rough estimates I’ve done my house would need around 90,000 BTUs. Most likely my propane boiler would still be needed but the stove would offset the cost a good amount.

begreen · Jan 24, 2024

If you are thinking Sedore, make sure they are still being sold. Legally they are not, at least not for residential use. Make sure the insurance company is ok with them too.

electrathon · Jan 24, 2024

Jvd850 said:
Square footage is about 2100ft. But that includes the upstairs. It’s a newer build from 2010 and an addition in 2020. I was told it was very well insulated when poured. I see on Sedore’s website they have a coil that could do up to 60,000 BTUs. With some rough estimates I’ve done my house would need around 90,000 BTUs. Most likely my propane boiler would still be needed but the stove would offset the cost a good amount.

Designed from 304 stainless tubing tested to 1500 psi, specifically formed and fitted to remove final heat from exhaust producing an output up to 15000 btu, It is frequently used for heating domestic water or boosting radiant water output,1″ outlet recommended when connected to radiant transfer coils, Solder connections.

This was the only information I could find on BTU output. I figure this can only happen with a raging fire, would expect about half that in reality. I couldn’t find anplace that hinted at 60,000 BTU‘s fron a coil. That would be a ripping hot fire, I believe the best transfer of the firebox heat to water is in the 5-10% range. I will agree though, even if the coil only put out 3% of the heat needed to heat your house, it is still heat. You would need to run numbers including all costs and maintenance to see if you would ever break even or hopefully get ahead. It may save you a few thousand to not tie the woodstove into the floor. I am guessing that the room heat might make the house warm.

My personal experience: I have a hot water in my shop ( not the one talked about in this thread). It puts out a lot more hot water than the one in my house. There is a small bathroom attached to the shop, about 5x8’ in size. Built very tight, well insulated. Concrete floor with 2” foam under slab. R19 walls, about R30 in the ceiling. No windows, quality modern door. I don’t heat it all the time, other than an electric heater set on 55 degrees. Hydronic floor heating off the stove. It takes about two days of 24-7 running the stove to raise the bathroom into the high 60’s. Never got it warmer than that.

Jvd850 · Jan 25, 2024

There's a separate coil for radiant systems "Designed from 304 stainless tubing tested to 1500 psi, specifically formed and fitted to remove heat from exhaust. Choose from 3 transfer coils producing outputs up to 30000 -60000 btu".

Thanks for the info on your system, I dont have any in person experience with this type of system. I've been looking into an OWB also but have the issue of getting the Pex piping into the house with it being on a slab. I would love to just get a normal stove but there lies the issue of having cold floors away from my stove. Everything on the ground level is tile. I loved heating my old house with wood, just trying to find the best way to do it now.

begreen · Jan 25, 2024

Jvd850 said:
Thanks for the info on your system, I dont have any in person experience with this type of system. I've been looking into an OWB also but have the issue of getting the Pex piping into the house with it being on a slab. I would love to just get a normal stove but there lies the issue of having cold floors away from my stove. Everything on the ground level is tile. I loved heating my old house with wood, just trying to find the best way to do it now.

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