Heat Pumps and Electric Heating - Rheem outside fan not running

Hey there everyone,

I have a problem with the outside fan not turning on when heat signal sent. I have an 11 yr old rheem RPKA-018JAZ. when looking at the unit I found nothing out of the ordinary. Pressed in the button on the contactor and the fan and compressor started running but would not continue to run when I let go of the button.

Question is how do I test to see if the problem is with the contactor, relay, circuit board or something else?

Not sure how long this has been an issue but my electric bill trippled this month in part due to the 5 deg temp days we had. During these couple of days the power went out for about 4 hours and bounced on and off a couple of time before it came on steady.

Also any idea where I could get the parts listed if they are bad

relay 42-21579-06
contactor 42-20044-20 or -02 not sure if I read that last # right
board 42-21776-06 or -09 cant read.

thanks in advance,

Cybertek

Is the compressor running? You say the fan isn't but you pushed the contactor in and both ran?

Check the drawing and see if there's additional switches after the contactor (temperature, pressure switches) some condenser fans won't run in the heat cycle all the time (defrost)

If it's that cold outside, the heat pump probably won't run anyway.

The compressor is not running except when I press the contactor button. the current temp is 55 out. As for the drawing, unfortunatly it has been removed...by mother nature of the previous owner or so..... and the other unit is the same as for the drawings.......

from what I can gather from looking at it.... the signal comes from tstat to relay then to the contactor then to the board and compressor/fan


Thanks,
Cybertek

Check for 24 volts to the relay coil,and the contactor coil.

If the relay and or contactor has 24 volts on the coil, then you have a bad coil. If you don't have 24 volts, check the tstat.

If it has an ambient temp tstat on the unit, check to see if it'sopen or closed.

Ok this problem is aggrivating....

I replaced the relay and the contactor and still the fan and compressor will not come on unless I manually press the contactor button...when I release the button the compressor and fan turn off

I checked and have 24v to the relay and contactor, retwisted the conections from the tstat to the outdoor unit.

When I press the contactor button the compressor and fan start and the heat that comes out of the vents is strong.

could this possibly be a bad defrost board? Is there a way to bypass the board to test this or anything else to bypass to test components?

Please help:confused:

Ok this problem is aggrivating....


I checked and have 24v to the relay and contactor, retwisted the conections from the tstat to the outdoor unit.

When I press the contactor button the compressor and fan start and the heat that comes out of the vents is strong.


If you have 24v and the contactor is not closing, there's something wrong. The defrost board just interrupts power to the outside fan, leaving the compressor powered up. ... It also flips the reversing valve to A/C mode.
The contactor (well, the simpler ones) just apply power. The power to the SOV, compressor and fan are all that is needed. There are temp switches and some have pressure switches to interrupt power to the compressor.
The contactor is controlled by the thermostat. Powered by a 24v transformer. You may see voltage, but there may not be enough amperage to move the contactor.

tom