Old thermostat wiring doesnt match up with new thermostat
My old wiring was as follows:
G, C, R, Y, O, W2 (with jumper to E)
My new thermostat is a Honeywell RTH7600 and I have no clue how to wire this. I wired it the way that I though it would go, but the heat comes on when the a/c is supposed to be on and vice versa. I'm assuming that a couple of wires are backwards, but I dont know which ones.
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Re: Old thermostat wiring doesnt match up with new...
Look at the instuction booklet (or on the T-stat board) for a switch for the reversing valve.
Some systems reversing valves are in cooling mode when energised, some are in cooling mode when NOT energised.
You are looking for the switch (Usually very tiny, or a different jumper setting) that will change the position of the reversing valve when calling for heat/AC.
This is not a switch like the typical "ON OFF AUTO, HEAT COOL EMG HT switches. It will be on the board itself or the back of the T-stat.
Re: Old thermostat wiring doesnt match up with new...
After you selected function 170 and set it to 7, your next function to set is 190( this is for your heat pump changeover valve) If you wired "O" to your O/B terminal, set 190 to 0, then press DONE. This should correct the problem.
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E Back up heat/ white wire
AUX Jumper to E
Y yellow wire / Cooling - compressor
G Indoor fan Green wire
O Reversing valve energised in cooling most units Orange wire
L unknown. consult your manual Leave open
R Main power Red wire
B Reversing valve energised in Heat Rheem units only.
C Common second leg of power Blue wire.
It depends on the equipment you are connecting the thermostat to. If you have a heat pump, the thermostat must be wired differently than if you have separate heating and cooling equipment. If you have a two-stage or modulating furnace (or boiler), the w and w2 wires will conect for heating, and the y and g wires will connect to the air conditioner. Naturally, some configuring must be done with the new thermostat so that it acts correctly.
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You need a 2 heat, 1 cool, heat-pump thermostat. W2 is the heat from the heat-pump unit outside, E is the emergency heat inside the house (usually electric), and on the new thermostat you just have the one W terminal for heat. You can jumper the two wires together (W2 and E from the old thermostat), but you will get both heats all the time when its being called for. Since you may have powered heating instead of powered cooling, I would try to get a thermostat that matches up better, otherwise, you might run into more problems than just the terminals, like rewiring the heat pump and furnace/air handler to accommodate the new thermostat. Hope this helps, and if you still have problems afterward, be sure to explain which wires were already hooked up to which terminals and so forth so we can have a little better idea whats going on, sometimes it can get confusing without being there. Good luck and hope everything works out for you!
Wiring on the old one, "X", probably a brown wire will not be used on the new stat. If it's a blue wire, this may be your common. "E" and "W2" probably wired together with a white wire, this controls electric heat. "R" with a red wire, this is 24 volt power. "O" is an orange wire, this is the reversing valve. "Y" is a yellow wire, this is the contactor. "G" is a green wire, this is the blower. This pretty accurate? On the new stat, the jumper should be connecting "RH" to "RC/R", leave it in and wire the "R" from your old one to either terminal. White from the old one will go to the "E" of the new one. If your electric heat doesn't work after the install, you may need to jumper the "W1" and "W2" with the "E". "O" wires to "O". "Y" from the old one wires to the "Y1" of the new. "G" wires to "G". "C" on the new one is common. Usually a blue wire goes here. If "X" on the old one was blue, plug it into the "C". If it was brown, I'd suggest not using a common, and installing batteries. Hope this helps.
sounds like you have a heat pump the w2 on old thermostat is for a second stage heat. If you can give me a little more information on type of system you have (forced air furnace with heat/cool, Heat pump or boiler)? How many wires are on old thermostat? Is it a no programmable or programmable? How old is the furnace?
both thermostatats will have terminal designators R,W,Y,G, possibly O/B, C, W1,W2, Y1, Y2, etc.
Simplest method is to remove wires from old stat one at a time. mark where they came from and then install at same desinated terminal on the new t-stat. Hope this helps. be sure to shut off power supply to the unit (furnace) first. The wire coming to the R (RH,RC) terminal is the 24 volt a/c hot, all others are feeding back to perform given function.
You have a heat pump. You need a thermostat for "Heat pump with Electric back-up heat". Make sure the 'stat has either an "aux" (auxilliary heat) or an "E"(Emergency heat) terminal. The wiring instructions will be provided with the thermostat.