Heating, Air Conditioning, Fridge, HVAC/thermostats


central nj ranch home family built in 86. giant florida room added on 3 yrs ago has separate forced air furnace and air.  no problems. ran baseboard in 77 foot long basement in 91 for heat only has its own thermostat-- no problems. major part of house upstairs is hot water baseboard two zones with 2 separate honeywell circles.  And the cenrtal air has two zones with its own two honeywell circles. now for the question.... have too replace the two air only thermostats, i think they are t87f's   with q539a-1469 subbases. What do i replace them with? Rather have non programable  basic stuff , but online i am having a problem cause most of the descriptions say no air only application. But i am dumb is this what single stage means even if it does not say air only?

The low voltage wire connections on a thermostat are pretty much as follows.
The "R" post is for the 24 volt power that is suppled by the unit it controls, be it a gas furnace or a boiler or a heating cooling unit or a heat only unit or a cooling only unit etc.
The 24 volt power wire  from the unit is most likely red since it is going to connect to the "R" post BUT it could be any color that the person who installed it used. I assume it's a red wire, The "W" post connection is for heat if there is a white wire it makes scents to use it for the "W" post if your unit heats. The "Y" post is for cooling, if there is a yellow wire it makes scents to use it on the "Y" post.
For a cooling only unit you can if available in your area go to Lowes, Home Depot, Ace Hardware or any like store and get a simple 24 volt "Heating and Cooling Thermostat".
Connect the "R" power wire and the "Y" cooling wire, set the indicator on the thermostat to "COOL ".
If the thermostat has a "R-H" and a "R-C" connection use the "R-C" post.

Heating, Air Conditioning, Fridge, HVAC

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Jim Barnhart


Fifty + years conditioning the air.


Answer questions about , residential and commercial. Answer questions about sheet metal fabrication. Fifty years plus experience. No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances, I don't specialize in one particular area of the HVAC area, I'm more of a General Practitioner, Limited in refrigeration/

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