hot water from my coal stove
 

i placed a 40 gallon tank on top my coal stove and preheat water before going into my hot water heater. i did this 3 days ago and have had my water heater shut off and i am getting all the hot water i neeed. frank

I used to heat hot water with wood and coal.. But, went to Solar hot water
and liked the fact there wasn't any clean up to perform.
I think that system lasted 15-17 years before dying.

http://i46.photobucket.com/albums/f1...HSTARMOT35.jpg

My multi-fuel boiler is just burning oil these days..
Heating both my domestic hot water and providing heat..
I'm waiting for a new heatpump unit to arrive. Hoping it's here before April..
And the end of the real heating season.

http://i46.photobucket.com/albums/f1...001smaller.jpg
This one had a leak.. :(

Don't forget that you can wrap a water line around the metal part of your chimney as well to capture that heat as it's otherwise lost.

water heater
 

here are some pics, low tech but effective. the cold water is diverted into the tank on the stove and comes out heated and goes into the cold inlet on the water heater. supplys all my hot water for 3 people.

hot water from my coal stove
 

hi,
Good idea

This is my low tech hot water heater. I put some pipe in my wood stove and connected a small circulator pump up to it. It's controlled with a snap disk to turn it off and on. From there it's pumped into an old 60 gal. solar water heater.

http://i4.photobucket.com/albums/y11...905_022034.jpg

How does it work out for you?

I get all my hot water from it in the winter. It heats the water in a couple of days of good burning to 140F and gets as high 180F at times. (Great for washing dishes in the dishwasher!) I could insulate the tank better than it is now to retain the heat longer but I never run out of hot water with it unless I leave for the weekend or don't burn for a few days.

All in all it cost about $200 in parts including the tank. (Found in newspaper ad) It saves me $10 in electric five months out of the year.

Very nice setup! What are the inlet/outlet temperatures? I have been thinking about doing something like this with my woodstove in the garage and pumping hot water in to heat the house, like those outdoor boiler setups. I just wonder if that setup transfers enough heat to heat a house.

Inlet and outlet temps stay around the temp of the water in the water heater. The whole system holds less than 4 gallons I'm guessing.

The pump is a three speed circulator pump set on the lowest setting. I'm guessing I could have put in more pipe in the firebox or need a smaller/slower pump. Some set ups use convection and I wanted that way but it just wouldn't work in this set-up.

Overall I am very happy with the results and it has more than paid for itself already.

Right now I have 3 extra people and 2 kids staying here and it doesn't keep up with the demand put on with the showers and dishwasher. But it is preheating the water going into the electric 40 gallon water heater to 90F to 110F...now I need to get rid of the extra people. lol

Well it's definitely putting out some good heat if its adding 40° to 50° to the incoming water during use. I tend to agree that the pump is probably putting some decent flow through the pipes, given the even inlet/outlet temps. Either way, it's an excellent retrofit for an old wood or coal stove. Definitely do-able on mine. I might have a go at it when I get some extra time and cash, just for experimentation purposes if nothing else.

do you have any other parts to the system for safety? what happens if the pump fails to come on? do you have to worry about a steam explosion or does something deal with the pressure?

It has an expansion tank built into the line. Also the fill is just a large pipe with a loose fitting cap.

I believe it does actually 'boil' the water out of the loop in the stove until the pump kicks on. You then hear the pipes pop alittle when the water flows into the pipe, but after that the system runs normally and very quietly.

No problems so far anyway...:D

I also got a line on a 75K BTU Carrier gas boiler with expansion tank, pump and 2 zone valves for $200. I hope the guy saves it until the weekend, can't get over to give the cash until then. I think that might work well for the house and/or garage for my "Plan B" back-up heat.

Then I can tell the city to take me off the hot water heat!:thumbup: Next step would be working on the electric then. Off the grid in town is the goal.

The expansion tank is only for minor variations in pressure. As strider was trying to suggest, if your pump failed (and there are so many reasons that this could happen) you would have a very serious situation on your hands... We don't hear much about steam burns anymore because we don't use steam much anymore. But my mother, who was a country doctor's assistant in the time when steam was in use, had some pretty grizzly tales about steam-power gone wrong... we're talking about arms and hands and fingers being cut off by high-pressure steam, and blindness and large areas of scalded skin.

You ought to be able to find a pressure relief valve from an old water heater... there is a reason they are required.

Safety isn't just for sissies anymore...

-AC_Hacker