Hi, have a Trane heat pump AC unit (WCY042G100BA)( serial # 3232XR91H). Come home Sat. evening and unit is running and blowing HOT AIR. Thermostat is set for cooling at 77 degrees, it’s 85 and still getting hotter. Turn unit off till next morning. Turn unit back on and within 2 min it is blowing hot air. Open thermostat and check voltage on wires to it. The RC/RH have 27 vac this is good. The O connection (white wire) has 21.8 vac this is the reversing value connection, this not good compared to my other AC unit. This wire goes up to the unit on the roof to a control board 21C140501G24 (CNT02516), Is this circuit board bad or is something else bad??? There is a 9 pin connector on this circuit board only 7 wires to it, 4 were 0 vac , the other 3 have 21.7 vac , 2 are black and 1 orange(was the white from the thermostat).
27vac on Rc/Rh to C is good.
21.8vac on O is a little low.
It's normal to see 27v open circuit and the voltage to go down when calling for cooling.
When you call for cooling you are applying 24v to the Y and the O wire.
If you can check at that stat and still have it operating.... Y and O should measure the same in cool.
I can't find the exact wiring diagram for your unit. I posted a link to a manual but it's only connections.
The O wire is the reversing valve. There needs to be 24v on the valve for cooling.
21.8v should be enough. 0v is a problem.
I have a feeling the small relay on that control board is for the reversing valve.
Can you post a picture of the wiring schematic or of the board ? How to insert pictures.
The reverse valve looks like the picture. It will be near the compressor.
The black part will be connected with two wires.
If you see the valve.... trace the wiring back to the board and test it for 24vac.
Hi, I have 2 AC system, the reading I have taken have the thermostat disconnected. the 21.8 vac on O is on the system that is blows hot air, the system that is keeping the house cool now has 0 vac on O. So the voltage I see on the problem system is from the circuit board in the AC unit on the roof.
PS the manual link seems to be infected.
Thanks for the help,
thermostat connected in off mode, thermostat connected in cooling mode,
O 22 vac 26 vac reversing value
RH 27 vac 27 vac power
Y 0 vac 26 vac heat pump
seems like O should be 0 vac in off mode?? Have 22 vac on O with or without the thermostat connected just seems wrong.
The problem right now is I can't go up on the roof where the unit is until Saturday, we just had the roof recoated, needs to dry.
Paul
Without the thermostat connected or in off mode..... there should be 0v on the O wire.
When the thermostat is in cool mode.... not even calling for cooling... there should be 24vac on O.
Apparently that power on O (22v) is coming from the defrost board. That is not correct.
Since you have voltage on the O wire and you supply power on Y and still get heat...
it sounds like your defrost board has a problem.
Was leaning that way. Reading the manual troubleshooting section almost all problems pointed to the defrost board/control board. Was thinking of buying one so I could replace it when I can get up on the roof again. Needs to be done early in the AM, We start the day out around 80 degrees. Sun City AZ. Now where to buy one.
Thanks again
Paul
Hello, I have a Goodman Condenser GSZ140601KE with Air Handler ARUF61D14AC controlled by Honeywell HZ322 Zone board. The defrost board is an Emerson/WhiteRodgers 47D01U-843. The 3 amp fuse keeps blowing after a few seconds with a cool call or a defrost cycle. What would be the best troubleshooting steps to sort out the issue? The unit heats fine as long as it doesn't go through defrost.
Thanks
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[i]Zone Board[/i]
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[i]Thermostat to zone board[/i]
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[i]Thermostat[/i]
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[i]Condenser[/i]
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Just got a new Hp and stat.
my old HP just had “heat” and would call upon the elec backup when required.
the new stat has auto, heat, heat+aux.
which do I choose in the winter?
and what is “dry” mode?
the stat manual and the air handler manual don’t talk about these functions in detail.
05-16-23, 09:14 AM
