I have a carrier heat pump.
Coming back from a trip the family turned on the thermostat to emergency heating as the only way to get the house warm.
Setting the thermostat to normaly heating, the outdoor condenser does nothing.
Main breaker in the breakerbox was tripped.
I reset the breaker, turned the thermostat to heating, went outside to observe the condenser unit, and only a slight hum was present (not from the compressor).
Not compressor activity nor fan activity.
When pressing the solenoid switch, a brief spark (indicating that there is a current going to the Condenser, and then nothing. Turned out that the breaker tripped again.

I noticed that the pressure on both High and low side is about 100PSI whereas the unit on the specs mentions 300 PSI high SIde, 150 PSI low side.

What can be the problem?

I noticed that the pressure on both High and low side is about 100PSI whereas the unit on the specs mentions 300 PSI high SIde, 150 PSI low side.


The unit specs are only for burst testing (max pressure) not for operation. From the sound of it your compressor might have bit the dust but further testing on your part or on the part of a professional HVAC person will be needed to be sure. Many units carry a 5 year or longer compressor warranty so find your purchase papers and you might save a few $$$ on the repair.

Naturally a bad capacitor,contactor,or other electrical device in the compressor power line could also be the problem that is why I suggested a pro look it over unless you have the knowledge and the tools to do it yourself.