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View Full Version : 2 wire Single Stage Thermostat Issue


RadMan
Nov 14, 2005, 06:04 AM
Thought this would be easy,

Here is the problem, the furnace stays on all the time even thought the programmable themostat is set at a lower temperature than the room. The wiring must not be correct but there are only 2 wires. One for the transformer and one for the heat control. Please help! Here is some information about my house.

I replaced a manual round thermostat with a Robertshaw 8600, Programmable Thermostat I have oil heat with an electric furnace with a Carlin EXPro Oil fired burner attachedand base board heating .

There were two wires connected to the manual thermostat, one to the R terminal and one to the Y terminal. I connected them as indicated in the wiring instructions, one to the RH terminal ( RH & RC terminals have a jumper between them ) and the other to the W1 terminal. There is a fan control switch that I selected Electric vs. Gas and a Heat Pump option switch that I have off.

What should I do?

Thanks in advance for your assistance.

RadMan

labman
Nov 14, 2005, 01:16 PM
Something is quite wrong. The Y terminal normally is used for A/C. The only way the I see old one would have kept the house warm would be if somebody connected in a relay to the W terminal at the furnace that gave power when the wire wasn't hot, and disconnected it when it was.

Go to the furncae and disconnect the wires to the thermostat. Turn the power to the furncae on, and see what happens. Then try it with a jumper between the 2 terminals the old thermostat was connected to. Post back, and I will try to figure it out.