A/C wont turn on unless I hold contactor in
#1
05-25-16, 07:29 PM
Join Date: May 2016
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A/C wont turn on unless I hold contactor in
My ac will not start when i turn the thermostat on. But it will turn on if i hold down the the pole on the contactor and it runs just fine, but i have to hold it down. I also do have a brand new furnace 4 moths old. Any help would be great thank you
#2
05-25-16, 11:19 PM
Group Moderator
Welcome to the forums.
Has the A/C ever worked since the new furnace was installed ?
Do you have a voltmeter ?
There are two wires in a cable going to outside unit. Those two wires need to be checked for 24vac when system is calling for cool. You can check them where they splice in near the electrical connection area.
Keep in mind that there is a five minute (maybe more) of a delay when the stat calls for cooling before the compressor starts up.
Has the A/C ever worked since the new furnace was installed ?
Do you have a voltmeter ?
There are two wires in a cable going to outside unit. Those two wires need to be checked for 24vac when system is calling for cool. You can check them where they splice in near the electrical connection area.
Keep in mind that there is a five minute (maybe more) of a delay when the stat calls for cooling before the compressor starts up.
#3
05-26-16, 05:01 AM
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I never tested ac after furnace got replace cause it was winter. And i will get voltmeter after work today test the volts.
#4
05-26-16, 10:51 AM
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Since you just had the furnace installed less then four months ago... you can also check with the installer too for repair help.
#5
05-26-16, 03:45 PM
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SO i used the voltmeter and it looks like im not getting 24volts to the contactor. SO would that be the wiring inside the house then?
#6
05-26-16, 03:59 PM
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There is a transformer that supplies the 24v. You need to check if that is burned out. If it is not then you need to check your thermostat to make sure that it is relaying the 24v when calling for cool.
#7
05-26-16, 04:05 PM
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Ok.... if you select FAN ON..... does the inside blower work ? If yes.... the transformer is good.
I'm pretty certain your system may be low on refrigerant. You measured at the contactor and did not find 24vac.
Now measure where the wires connect to the unit from the house with wire nuts. This will confirm if the problem is inside or outside.
I'm pretty certain your system may be low on refrigerant. You measured at the contactor and did not find 24vac.
Now measure where the wires connect to the unit from the house with wire nuts. This will confirm if the problem is inside or outside.
#8
05-26-16, 06:30 PM
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not sure what you have there but if it is an attic air handler it might be as simple as the float switch in the drain pan not installed correctly. I have heard that some installers get in a hurry and do not do a proper startup check. They could have left the switch laying loose in the pan wedged against the side or something LOL.
