Trying to install a Honeywell rth 2300 and a headache

Old 10-29-17, 12:37 PM
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Trying to install a Honeywell rth 2300 and a headache

The Mercury thermostat on the wall has a blue wire connected to o then a red yellow green and white wire connected to their appropriate letters on the old thermostat however the instructions on the new thermostat don't make any sense and I tried to hook it up and couldn't get it to work so I put the old one back on and now I can't get my heat to work. help!! Please
Old 10-29-17, 12:47 PM
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Welcome to the forums.

So your wires are labeled with letters as recommended in the installation manual..... correct ? A picture of your old stat base with the wiring connected is a big help.

Is this correct......
R = red
Y = yellow
G = green
W = white
O = blue

In looking at your wiring.... you have a heat pump system with back up electric heat. The 2300 will run a heat pump but cannot control back up heat.

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