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-   -   Outdoor AC on whenever heat is on - wiring problem? (

SammyLi 10-12-2008 11:35 AM

Outdoor AC on whenever heat is on - wiring problem?

after I had my furnace serviced 2 days back, I notice this odd thing. When I switch the themostat to heat mode and the heat kicks on, my outside AC unit also starts. I have never seen the outside AC on in cold weather like these days. So something seems wrong. I am guessing that the technician may not put the wiring properly when he's done. He did have to unwire the board so he can take out the blower. So I checked myself and here is what I found.
The 4 wires from the themostat seems to all connect to the terminals on the furnace's control board properly. I have outside AC unit and also a humidifier. I notice that the white color wires of both AC and humidifier connect to "C" terminal of the control board. That seems OK as I understand. But the red wire from AC goes to "W" terminal and the red wire from the humidifier goes to "Y" terminal.
As I saw from other posting, "W" terminal is for heat and "Y" terminal is for AC. So I am guessing that those two red wires from AC and humidifier should be swapped. That would make more sense to me: humidifier should be on only when heat is on and AC should be on only if the themostat is on "cool" mode and decides to kick off the AC.
Am I right about this?


beenthere 10-12-2008 11:45 AM

Yea. He just mixed up the 2 wires.

They need to be switched back.

But, he pbviously didn't check for proper humidifier operation.

If you decide to change them yourself, fine.

But, a polite letter to the company, will help both that company, and that tech.

If the company doesn't hear about the mistake, they can't help their techs to do a better job.

SammyLi 10-12-2008 12:18 PM

Thanks for getting back to me so quickly. I will call them tomorrow.
I totally agree with you that the company and the technician should hear about this so they are aware that they have room to improve the quality of their service. In this case, since the control board controls 3 modules, they all need to be tested if its wiring is touched. the technician obviously did not do that.

beenthere 10-12-2008 12:29 PM

PM's are somewhat boring.
So after a while, some techs short cut.

Unfortunately. It reflects worse on the company, then the tech.

By helping the company, you help yourself and other customers. No reputable company, wants to short cut their customers.

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