I HAVE A RHEEM CENTRAL A/C UNIT OLD UNIT , DOES THE COMPRESSOR CONTACT RELAY ALSO POWER UP THE AIR HANDLER ?

Check the start capacitor for proper value and replace if necessary.
Ditto for thermostat. There are also some fuses in the air handler that might need replacement.

You may have had a power surge that had a bad effect on electronics of unit. Make sure that unit is receiving power for one thing. U might try to reset the electronics by completely shutting off all the breakers to compressor and air handler and waiting a few minutes and then reconnecting.

Can you give me info on the unit

HI Lawrence did you check to see if you have the right power going
to the unit

Sounds like a relay inside the air handler is stuck 'closed'...

I would pump it down to the compressor then change out the valve instead of going through the whole recovery process and make sure the service ports are closed tight

II assume you mean the outside unit is running. if so turn off your system immediately. If no air is coming out of the registers, the blower motor in the air handler is not running and/or the system has froze up. Check to see if you have any ice on the large copper line coming out of your inside unit. There will be rubber insulation on it but just pull it back on the pipe right at the inside unit and you should be able to see ice. Take the service panel off the air handler(inside unit) and turn fan on at the thermostat. There is an "on" and "auto" fan switch on the thermostat. Go back and look in the air handler and see if the fan is running .If it is then you have a refrigerant problem. If the fan is not running then it will be a run capacitor, bad motor, no 24 volt power to relay, bad relay, bad thermostat, bad board if fan relay is solid state, or a bad conductor from the thermostat. Hope this helps. You will probably have to get an a/c tech to troubleshoot either of the above problems more thoroughly to correct it permanently. If the system is froze up and the fan is working then the system is low on refrigerant. This means the system has a leak. The leak will have to be found and repaired before the system is recharged or the refrigerant will just leak back out again.

sounds as the the compressor gave up the ghost .. Out side fans running? does the compressor run?

It is possible that the relay in the thermostat for "cooling" has gone bad. The relay that runs the blower is different than the condenser relay. Check that you have 24v AC coming from the t-stat to the "y" terminal at the air handler. That same "y" wire should go out to the condenser, make sure then that you have 24v out there. If you have 24v at the condenser then see if the contactor is pulling in. If not then you may have a loss of charge switch that is stopping the current to the contactor. See if you have 24v to the coil of the contactor. If the contactor is pulling in and power is going to the compressor then the compressor has failed. If this is the case the condenser fan will be running but the compressor is not. If neither the condenser fan or the compressor is running then you have a problem in the 24v circuit, which could be a bad wire or a safety switch.

As you can see there are a number of possibilities for your problem. You will need to methodically go through everything to eliminate the possiblities till you isolate the problem,

I hope that this will help you to solve your problem and get you cooling again!

Thanks for using Fixya!

Heatman101

If you are refering to the indoor fan that is not running, but that the outdoor condenser is operating, the next place to check is the circuit board in the air handler, this is the control for the fan motor. the relay may be bad that actuates the fan circuit. if the relay is bad there will be no power to the fan motor. If you have power to the fan motor then the motor is bad and the motor and capacitor should be replaced.

Check the fan relay switch in the air handler.
Check the fan motor capacitor.
Check the fan blower wheel for binding.