combining two thermostat into one thermostat

john_112

i have one pipe steam heating system. i need to wire(combine) two thermostat in to one. please show me how to wire it. please give me the detail since i have no experience or knowledge of it.. thanks i did wire thermostat before. but not the boiler end of wiring. i going to cut the first floor thermostat. and control both first and second floor. on the second floor thermostatt please help

Jamie Hall

It's not that hard...

but I will proceed here in hopes that you know something about electrical work.  It is possible to do some considerable harm to the the thermostats, if not to the boiler controls, if you make mistakes.



First off.  It is much easier to do if the two thermostats are the same.  Just easier.  Second, and much more important, they should have been wired with the same colour codes.  So the first thing to do is to check and make sure that that is the case (note that if they are not the same, or if the colour codes are different, it doesn't make it impossible, just a little trickier -- and from the tenor of your question, I suspect it might be a tad too tricky).



Now.  If these are two wire thermostats, the procedure is fairly simple.  Usually you will be dealing with a red wire and a white wire.  Turn off power to the boiler.  Then pull the fuse or turn off the circuit breaker to the boiler.  Now.  You have one pair of wires from the boiler control to the existing thermostat -- red and white.  Cut those wires at some convenient location where the wires from the new thermostat can reach.  Hopefully it too has one red wire and one white wire.  Connect all three red wires together with an appropriate wire nut.  Connect all three white wires together with an appropriate wire nut.  You should be good to go.  Turn the boiler power back on, and try.  First turn one thermostat up; the boiler should fire.  Turn it back down; the boiler should stop.  Do that with the other thermostat -- should have the same result.  Set your thermostats at whatever you want; if you don't want one of them to do anything at all, just turn it way down.



If you have three wire thermostats, the procedure is much the same -- but that third wire will be a constant voltage supply, so it is even more important that you get the proper wires connected together.

john_112

Two thermostats into one thermostats

I have two thermostats in control. I want to make them into one thermostat. Not putting two thermostat on. I want to take one thermostat off. Then control both floor with one thermostats

john_112

Two thermostat

Why do I have two thermostat on this one steam heat boiler?? People said. One steam boiler can only have one thermostats ???

Jamie Hall

Multiple thermostats

There is no reason not to have multiple thermostats controlling one boiler -- that's what this museum I run has.  As I said earlier, if you don't want to have one active, simply set it very low.



If you want to have only one thermostat, though, just disconnect the wires from any thermostats you don't want, and connect only the line from the one you don't want.  No mystery in that.