hs tarm add on boiler

matt_23

I obtained a hs tarm add-on wood fired boiler. I have an old gravity fed coal conversion boiler in place. The in and out piping on the old boiler is large, 5" plus in diameter. How and where can I tap into this system. Would I also need a circulator or would that screw up the delicate balance of these ols systems?

Al Letellier

add-on Tarm

BE CAREFUL!! Adding a circulator anywhere in the heating loop will change the flow characteristics of the entire system, and using a add-on without a circulator is looking for trouble. The Tarm will heat water too quickly without proper circulation and will blow the safety, or worse, the firo plug at the top of the firebox, and that's a mees you don't want to have to clean up. You need to consult with a heating pro for this project. Converting to forced hot water may be your only option to do the job safely.

Harold

Just a thought

That wood boiler is best used at full firing to keep creosote down and efficiency up. You can use the internal control to automatically bank the fire but it has the above mentioned bad effects. At full burn it will dump a very large amount of BTUs in a relatively short time. The way to store this is in a large insulated non-pressurized tank. The furnace dealer sells one (not cheap) or you could build something out of an old tank or something creative.

Do this and you now have a nice high temp tank of water to work with. Some ideas - install a coil heat exchanger in the output pipe of the boiler with a circulator to the heat storage tank. Have a "fat spot" fabricated to go into the piping to hold a larger coil. Let gravity have its way with the heat in the old boiler system. Same general approach but with an external flat plate exchanger and another circulator injecting hot water in the same general place. This lets gravity work the way it used to.

Issues - getting the water in the heating system pipe hot enough and containing enough BTUs. You are going to heat up the water in the old boiler somewhat and this will be a source of losses. Coordinating control of the old boiler and wood boiler storage tank.

You probably ought to talk to someone that knows how this all should work.