New Thermostat is working backwards?

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  #1  
Old 10-29-20, 05:26 PM
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New Thermostat is working backwards?

I recently moved into a new condo with baseboard boiler heating and wanted to change out the old Honeywell thermostat with a cheap programmable one (Emerson 1F78-151 5-2). After installing the Emerson the heat turns on when I set the thermostat below the apartment temperature and the heat turns off when I set the thermostat above the apartment temperature.

There were only two wires connected to the old Honeywell. A black wire connected to R and a red wire connected to Y. When I looked at the instructions for the Emerson it said when installing a two wire system connect to RH and W so I connected the black wire to RH and the red wire to W. Once I noticed it was working reversed I tried swapping the red and black wires but it still seems to be working backwards. Does this thermostat not work with this system? Any help would be appreciated.

Old Honeywell Thermostat

Honeywell Thermostat Wiring

New Emerson Thermostat (RH is the connection to the right of W)
 
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Old 10-29-20, 05:50 PM
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Welcome to the forums.

Your old thermostat was for heating only. They used the COOL mode to run the heat.
Honeywell T822 manual (pdf)

You wire the new stat the same way and set the thermostat to cooling.
You don't need red jumper. Connect to Rc and Y.
 
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  #3  
Old 10-30-20, 02:50 PM
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I did what you suggested and it seems to be working properly. Thanks for the quick solution!
 
 

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