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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8385
Experience:  Furnace, A/C and heat pump specialist.
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The a/c unit outside does not come on when we turn

Customer Question

The a/c unit outside does not come on when we turn temperature down. I already checked the wires and I have 240 going to unit. is it in the thermostate?
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

First step is to see if we are getting 24v control power to contactor to energize it.

Customer: replied 1 year ago.
you mean 240volts!!!
Expert:  airheatman replied 1 year ago.

No. 24 volts. The contactors have 240 volts going in at all times.

On call for AC the thermostat sends 24v to the coil on side of contactor to energize and close the contactor to allow the 240v through to run fan and compressor.

Customer: replied 1 year ago.
where is contactor???
Expert:  airheatman replied 1 year ago.

In outdoor unit. Give me model and I can tell you exactly how to find them

Customer: replied 1 year ago.
Expert:  airheatman replied 1 year ago.

Remove service panel on corner. Check where the two smaller thermostat wires connect on sides of contactor as shown previously for 24v ac.

Customer: replied 1 year ago.
Thank You Problem was There at conductor, bad connection
Expert:  airheatman replied 1 year ago.


If you have further questions, please let me know.

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