I have an old Heat Pump System. Outside unit installed in 1985, inside unit replaced in 1998. A couple of weeks ago I replaced the old Amana mercury thermostat with a Digital Programmable from White-Rodgers.

All seemed to work well until this evening. Now on heat, cold air comes out. I watched the thermometer go from 70 to 63. I do not think it is a case of heat pump blowing air cooler than body temp but still warmer than room air.

Copper pipe coming from outside unit into house is ice cold. Aux Heat works just fine.

Had:
Amana
T874C 1059
Qq74F 1022 sub-base

Replaced with:
White-Rodgers 1F82-261

Amana White-Rodgers

Y1 (compressor) ----------> Y (compressor)
W1 (Heat Relay 1) ----------> O/B (reversing Valve)
G (Fan Relay) ----------> G (Blower Fan)
R (Hot) ----------> R (24v Hot)
W2 (Heat Relay 2) ----------> W2 (Aux Heat (W2 Jumpered to E)
X1 (Check LED?) ----------> C (24v Common)


I am sure about the wire labels on the Amana, but not sure about what they do, the stuff in parentheses. Best I could figure out from the Internet.

The White-Rodgers is exactly as I wired it, with the stuff in parentheses coming out of the manual.

Here is my thought: On my old system I never had to flip a switch on the thermostat to go from cool in the summer to heat in the winter. It did it automatically. The replacement thermostat does not have that capability. During winter months here in Mobile Alabama (where I live) it often gets warm during the day and cold at night. Today was a day like that. Is it possible that the system tried to go to A/C today, and come night fall was looking for a signal to switch it back to heat that it did not get?

Any ideas?

 

Your labels are correct. On your new thermostat, y is used for cool and stage 1 heat. O is reversing valve, powered whenever the tstat is in cool mode. If you hooked the wire that was on w1 on the amana to o on the white rodgers then you are air conditioning on first stage heat. To test just disconnect the o wire in the tstat. Oh and disconnect the wire from the c terminal. If the unit is wired to send a signal in case of heat pump lockout it will blow the fuse in the tsat. You could just go to the air handler and switch that wire over to c. Good luck This may take rewiring totally at the air handler. What make/model do you have?

 

Thanks for the prompt reply Thermofridge.

I not sure on the make,model of the outside unit. Looked and did not see anything that indicated? I may have to take a cover plate or somethig off?

On the inside unit, it is a Carrier FB4ANF036.

I put the old thermostat back on, and all seems to work ok? I think you are right on the money. Hower, the thermonstat was only 70 bucks. Wouldn't it be easier to just find one that works with my system versus re-wiring (something I am not qualified to do)?

 

It is always preferable to get a new tstat that will directly replace the old one. However, the person you buy it from needs to understand your system in order to give you the right one. If you can, go to a carrier dealer with all the info you can gather.