Heating, Air Conditioning, Fridge, HVAC/residential A/C


Changed thermostats this past weekend for the two units at my home (one up and one downstairs).  Worked fine for 4 days, until it got cold this past Wednesday, both systems decided to stop working.  I am using a RTH3100C Honeywell thermostat and have a FA4ANF060 Carrier furnace.  Has a heat pump/heat strip set up.  Buzzing noice at my condensor tells me its getting power.  But when I touch red and green thermostat wires together the fans does not come on?  Nothing wrong at the breaker box.  Appears something is not getting power between my furnace and thermostat.  Both thermostats and units acting the same way - liklihood of both thermostats being faulty is highly unlikely.  Both units working fine prior to thermostat change, confident I using right thermostats.  Called Honeywell - all is hooked up right.  I am very confused on what to do?

The color of thermostat wires are not always as they should be,
99% of the time the R post on your thermostat would have a red wire but any color of wire would work as long as it was connected to the R post on both ends, common sense would be to use a red wire but there are some goofy installers out there.
on the thermostat the R post is for the 24 volt power coming in to the thermostat, when you set the thermostat to Heat the power switches to the W post, If you touch the wire from the R post to the wire from the W post you should get heat, A good idea is to take the R and W wires off of the thermostat before touching together to keep from possibly frying the thermostat.
Touching the R post wire to the Y post wire should give you cooling.

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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