We had furnace replaced over the winter. Thought everything was hooked back up properly. But now when we turn on air conditioning we can hear fans kick on in furnace and it blows cool air through vents for a few seconds, shuts off, and comes back on for a few seconds. Over and over and over again. But the outdoor unit does not kick on at all. Any ideas?
Outdoor air conditioning unit not kicking on
- Thread starter meridith
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DonL
Jack of all trades Master of one
The outdoor unit most likely has its own 230v breaker. Was it tripped ?
If it has never worked, It may be wired wrong.
Good Luck.
If it has never worked, It may be wired wrong.
Good Luck.
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Jadnashua
Retired Defense Industry Engineer xxx
There are two low-voltage wires that go to the outside unit. The thermostat, when in cooling mode, applies 24vac to the yellow terminal (usually, the cable has a yellow wire, but it doesn't have to be!). That goes to both the furnace, which tells it to turn the fans on, and outside to turn the a/c unit on. If the yellow 24vac and the return line aren't getting to the a/c unit, it will not turn on, so that would be the first thing to check after verifying that the circuit breaker to the a/c unit is not tripped. If that control voltage is getting there, you should hear the power contactor energize when the thermostat is calling for cooling. If it is, and you have 240vac available, it could be one of several things: the contactor is shot and is not applying the voltage to things so they can turn on, or the compressor is bad, but if neither the fan in the a/c unit nor the compressor run, it's more likely power is not getting to them. Course, they both could be bad. One spring, mine didn't work. I opened things up and found a mouse that exploded as it walked across the power contactor...it's guts had gummed up the power contactor so that it couldn't activate. Cleaned things up, and it's been working for years since.
samuel123
New Member
There might be some defect in heating coils. When you got furnaced replaced in winter, didn't have you check its heating system. It might be some minor defect and it will be better for you if you get it checked from professional electrician.
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