I have bought two new thermostats to replace my old worn out ones. We have a oil burner furnace with hot water radiators around the house. No cooling. The problem is that the two thermostats have different terminals. Especially the lack of the "RH" terminal on the new one is confusing. I have attached pictures of the old and new thermostats. The old is still connected as it was. The black cable stump connected to "RC" on the old thermostat goes nowhere it's just there. I have one thermostat on each floor in my house. They are both wired the exact same way. My question is how do I connect the the wires to the new thermostat that doesn't have the RH terminal. It has G, O/B, Y, W, RC and R terminals. See pictures below. The old thermostat on top connected as it was. Maybe the new thermostats aren't compatible with my system?

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1 Answer 1


R = RH for you

Simply connect the wire that connected to RH on the old thermostat to the R terminal on the new thermostat, and then connect the wire that connected to W on the old thermostat to W on the new thermostat, and you should be good to go.

  • Thank you so much. Makes perfect sense. I have another question about the thermostat replacement, but belongs in a new question.
    – Christian
    Feb 22, 2019 at 13:47

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