O.K I just got done building a wood boiler/ furnace for my garage and I have a couple questions. First one is, I made My own heat exchanger with a fan mounted behind it. What is the switch called that mounts to the copper pipe that turns the fan on when it senses heat in the pipe? Second can I use this HONEYWELL HEAT ONLY THERMOSTAT MODEL CT410B to turn on the circulator pump when the thermostat calls for heat? Any help or advice would be great. Thanks..
A water temperature sensing switch is called an aquastat. To be safe, you need lots more controls than you are discussing...
Let's say you have the wood boiler running, but no call for heat. If you just let it sit there, you'll start to generate steam and blow things up! So, you may need to run the circulator constantly, and maybe dump the heat somewhere if the house doesn't need it. Trying to roll your own can get you in trouble with your insurance company, your building inspector, and your life...not counting blowing up your house.
I have a aquastat that runs blower to get the fire burning. that is the problem the circulator pump runs all the time and the fire cant keep the water warm enough, it runs about 140 unless i unhook the pump. the water gets to 170 then the blower shuts off and the water stays right around 170. I really just need a thermostat that will run the circulator pump.
The problem you will have is when the thermostat is satisfied and the circulator stops running with the fire burning the boiler will over heat causing a dangerous condition.