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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22678
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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my thermostat O/B swith is manufacturely set at O. Can you

Customer Question

my thermostat O/B swith is manufacturely set at O. Can you tell me if on Rheem model # XXXXX if the O/B switch should be in the B position?
Submitted: 8 years ago.
Category: HVAC
Expert:  BillyHvac replied 8 years ago.

Usually the "O" terminal, when set up ,is to energize the cooling relay for air conditioning. The "B" terminal is used to energize the heat terminal if set up that way.

Most all units have the "O" set up for cooling, so that if the valve fails, it fails in the heat position so you always have heat.

The compressor runs during heat and cool on a heat pump, and it is up to the reversing valve to choose heat or cool. If you live in a cooler climate, odds are you are setup with the rheem to have the "O"


BillyHvac and 4 other HVAC Specialists are ready to help you
Customer: replied 8 years ago.

Billy was just great he answered my question in a very speedy manor. I wilkl definetly use this site again.... Thanx Billy


Eleanor Burke

Expert:  BillyHvac replied 8 years ago.
I appreciate your kind words.

I thank you.