Air Conditioning - Rheem Outdoor Compressor Won't come on

My Rheem unit was working fine. It is just past five years old but we have had several brown-outs and power surges lately. When I turn the unit on, the indoor runs but the outdoor unit does not. I have checked the power and there is definitely juice getting to it. When I close the contacts, the compressor runs, but the fan does not. When I give the fan a push it does power up. But I can't get the indoor thermostat to close the contacts on the outdoor unit in the first place. Any suggestions?

If you have a voltmeter, have the thermostat set to have cooling & check for 24 volts ac between the two small wires coming from the house to the contactor on the outdoor unit. If 24 vac is present, replace the contactor. It also sounds like you may have a bad fan capacitor.

I have 24V showing on both the red and yellow. So, just for the sake of clarity, you think I need to replace both the capacitor and the contacts? The capacitor was my first guess but the contacts not closing is what had me puzzled. Ballpark and non-binding estimate for parts cost? Also, is there a safety switch installed that prevents the circuit from closing if the unit is low on freon? I do not suspect this, just asking.

Change them both while you are in there. It's cheap enough. Wholesale costs are about $15 for the contactor and $5 for the capacitor, depending on which models of each. It will save you the headache of diagnosing and changing the other next time...

There is on some equipment a high &/or low pressure switch will lock out the unit. Without seeing a wiring diagram for your equipment I wouldn't know if your's has either or both. If you have a dual capacitor (three sets of terminals) the capacitor cost would be higher. When possible, I like to install separate caps for the compressor & fan. Duals fail far more frequently than do singles.

Grady,
It sounds like it may be a freon problem then in conjunction with the capacitor. I have two; one is a Mallory 330Volt two terminals with a diode or dohickey jumping across the top This one is connected direct to the fan motor and to the other capcitor. The other is a 60/5 with three terminals. I did a test on my contacts by removing them and jumping them across my yellow and brown inside. They slammed shut without hesitation. When I take a reading outside at the board where the wires attach from inside, my brown has no voltage alone and my yellow has 25V. When I touch test the voltage between the two I still get 25V. However, when I have a call for cold air on the Tstat and my indoor unit is running the terminals on either side of my contacts show no voltage. This leads me to believe that I am not getting control voltage which I figure either the board is bad or there must be a lockout.

The Mallory 330 volt sounds like a start capacitor.
It seems real strange to have a start cap hooked to the fan.

Pressure switches are usually clearly marked on the wiring diagram. Even if they are not, you can often find them by tracing the low voltage wiring. Pressure switches would be attached to the refrigerant system. They can be checked for closure with an ohm meter.

Is this by any chance a heat pump?

Yes, I apologize, I should have said that it was a heat pump in the beginning. Is there a means to reset a pressure switch, or does it mean I need a recharge on the system?

Most are automatic reset. If the switch tests open & there is no reset button, either the switch is bad or the charge is significantly off.

Grady, you are the man! I found the switch tucked away in the crevice between the house and the housing that I had not fully removed. I still need to replace a capacitor to get the fan going on its own, but I feel like that in conjunction with a rapid fire on-off of the current the other night by utility company caused the switch to trip. I pushed the reset, and called for cool and the compressor started. After a slight push of the fan, the unit started cooling. I take it, I need to change the three pole capacitor (60/5) instead of the Mallory?

On the fan motor should be some markings as to what capacitor it is supposed to take. A typical condenser fan motor uses between a 5 & 10 microfarad capacitor at either 370 or 440 volts. You can use a 440 without problems even if it calls for 370. The three terminal cap also sounds like an odd ball. I suggest you take the model & serial #'s of the unit to a Rheem dealer who can look up the correct capacitors for your equipment. This piece of advise presumes the compressor & the fan motor are original equipment or exact replacement. If you have any question that this may not be the case, get the numbers off of the compressor as well. Any decent supply house can look up the compressor numbers & tell you the correct cap. If I had to guess, I'd say some "repair" work has been done on the unit.

New Capacitor, Called for cold and got it! All is well and just in time as we are looking at 90's today.

Thanks Grady. You are a handyman and a scholar.

My gosh that is a success story, very encouraging, let me be the first to say GOOD WORK MAN
Former Member thinks this is a AWESOME website what do you think guys?

Way to go. Glad you got 'er going. It's always my pleasure to work with someone willing & able to work with me. The ability & willingness to use a multimeter goes a long way. It makes my job so much easier. Thank you.