Big E homemade boiler conversion

[brack86svo]

We bought a house with a Big E installed in the basement, with no way to distribute the heat through the house. I installed a central air system in the summer. Using a snorkle on the return side of the air handler, I was able to distribute the air through the house. The other issue was, while it was heating the first floor to the set temperature, the upstairs of our cape code was too cold for our daughter. I wanted to heat water with the stove and use that to distribute the heat more evenly. I didn't find much in the way of doing this. You can buy a pellet boiler (that will be what replaces this stove when the time comes), or buy a crosslink conversion kit for $1800. I tested different coils and setups till I came up with one that works well.

My first coil was made from a 10ft piece of schedule 40 pipe. I filled and packed the pipe with sand, heated it, then bent it into a loop. This coil was not very efficient. I was only seeing about 5 degrees of temperature rise from the water going in and coming out.


My next coil was a 25ft 3/8 stainless coil I got from McMasterCarr. I bent the tube into a coil with a hand tube bender that was capable of 180 degree bends. I don't have a very good picture of it though. Here it is installed in the stove. I was surprised to find that I was not getting much improvement over the previous coil. I assumed with the longer lenght, causing the water to be in the stove longer, it would create more rise.


Finally, I decided to add even more volume inside the stove with a tank. The picture isn't great. I made a rectangular box from flat stox, welded a 1/2 schedule 40 pipe for output, then drill the box at the other end, and welded the stailess coil from above into it.


With this setup, I am seeing a 15 to 20 degree rise in temperature. I am running the stove off a thermostat, with the stove set to on/off. When the thermostat calls for heat, it turns on the stove and the 007 Taco pump. I used a snap disk to control temperature. When the water reaches 140 degrees, the snap disk closes and turns on the blower in the air handler.



I have a 10 gallon water heater that I got used off of CL to add volume to the system. I have been working on this for the past couple of months. Once winter is over, I plan to start over with the install to clean it up and make it look nicer.

All said and done with what you see here, I have about $700 in this project. That doesn't include my time but, I had fun working on it. I will invest more into it over the summer. I plan to add an aquastat as protection to turn the stove off if the water get too hot. Right now, I have a 20 psi pressure valve that is plumbed into my sump pit but, I'd feel better if the stove turned off if the temp got too high.

Any questions, feel free to ask. I understand the dangers of a boiler, and the fact that my insurance company would not like what I did.

 

[brack86svo]

There is a 210 degree valve in the water heater, and a 20 psi valve I plumbed in.

 

[BoilerMan]

This is interesting, where are you putting the "water heat exchanger" into the stove? It's stuff like this that makes America GREAT! People with some fabrication skills and some brain cells to think out of the box and make do with what they have to get the job done! Are you heting baseboard up there, or some type of low temp emitter?

TS

 

[brack86svo]

I have a air to water heat exchanger in the plenum of the air handler to distribute the heat through the house.