Contactor will not engage i have 240 at contactor and 19v at thermostat

Stuck contactor most likely or thermostat still engaged. Tap on contactor to see if it releases. Call Aire Serv if not

the is a 24v wire that feeds from your thermostat to your unit, inside there is a contactor that engages, this makes a click sound as it really is a basic mechanical part the makes metal touch metal to allow current to flow through the system, perfectly normal, your hearing the low voltage engage the highvoltage at the contactor.

Hello,im assumimg you are referring to the contactor coil on the oudoor unit. First you must verify if the coil is receiving 24 volts from the thermostat at the coil terminals, if not there is a problem with the low voltage circuit, possibly a a open thermostat wire or a fuse blown on the indoor control board. If ther is 24 volts at the contactor coil and it does not engages then the contactor coil must be replaced

Sounds like the contactor is stuck. Turn the power off on both units and remove panel on condenser. Pull out on the contactor if engaged. Likely still needs replaced, it's going to happen again.

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You are talking about the low voltage transformer

I am assuming that this is the condenser(outside unit)? You will need a multimeter, take off the four screws and at the contactor measure and see if you have voltage. I am assuming the contactor is engaging, if not push in contactor. Fan and compressor should come on, if it does the you will have to check for 26 volts on the contactor where your thermostat wires come in, if you have the volts then the contactor is bad. Hope this helps Tim

On A/C units, there is a low voltage line that leads to a contactor, which engages to close the high voltage circuit to the condensor unit. Over time, the accual contacts in the contactor can weld themselves together. Try shutting off your furnace breaker but leaving on the one for the outside condensor unit. If it still runs, your contactor probably needs replaced. Contact a licensed electrician or HVAC contractor and tell them you think your contactor is in need of replacement. Is a fairly simple and quick replace, but the contactor itself is not cheap.

The contactor engages from low voltage power from the thermostat as does the outside condensing unit. You may have blown the low voltage transformer or have a loose thermostat wire. Check line voltage(220 volts) to the transformer. Check load voltage(24 volts) from the transformer. If no voltage out,replace the transformer. If you have voltage out(24) check the thermostat wires and the thermostat. If you have a digital thermostat there is a 5 minute delay in the thermostat after power is restored before it activates.

Is the contactor engaging? Make sure it is getting 24v. If not, check the low pressure safety, outside thermostat (if you have one) and the defrost board. Follow the low voltage from the thermostat to all these controls, up to the contactor. Check the thermostat too. If you need a walk through I can help, if you have a volt/ohm meter.