Compressor and Fan not working)

Old 05-09-14, 11:25 AM
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Compressor and Fan not working)


I have a Lennox Heater/AC unit on the roof of my office.
Now that it's getting hot, I switched to AC and notice that both the fan and compressor are not running. I have a little device connecting both to the fan and compressor with a little black button on it. When I push on it, both the compressor and Fan works.
So does anyone know what can be the problem? Capacitor? or my control unit Honeywell (W7212A1033)

By the way, I paid someone to come and check out my unit. They came, did some test on the machine (gas pressure, electricity). They left took my money and never came back. I guess they can seem to know the problem.
Old 05-09-14, 12:18 PM
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What you are describing is probably the "contactor". It is energized by low voltage fed from the inside unit through the thermostat. You should be able to see 2 small thin wires connected to it. When the thermostat calls for energizes the contactor which feeds high voltage to the compressor and fan through a capacitor. You should be able to see it pull in when that happens.

Do you have a multimeter and know how to read voltages?

It could be something as simple as a broken wire inside or just outside the unit. Happens often with animals chewing it or a hit from a weedwacker.

Also, check your fuses and/or ckt breaker as well as the disconnect near the unit if you have one. They may have flipped them off during the service and not turned things back on.
Old 05-09-14, 12:56 PM
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Can you post a photo of the little black button ?

Does it cool when you push it ?

Did the RTU ( Roof Top Unit ) heat properly this last winter ?

God bless

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