Weird Heat Pump Action

My heat pump is 5 years old and worked fine last season. This season, its acting weird. When the heat is on, the outside unit will run for about 10 minutes and stop. But the inside vent blower doesn't run. after about 10-15 minutes the outside unit will do the same again. The inside vent blower won't run untill the outside unit cycled a few times like this. I also hear viberation noise when the vent fan starts, but the noise goes away at full speed. Does anyone know what the problem could be?

Also, for cost saving purpose, is it better to keep temperature static? Because the Aux heat will be on if the temperature difference is over 2 degrees.

Thank you

 

Yes.... it's best with a heatpump to leave the thermostat at one heat setting rather than using setbacks.

It sounds like you are having a problem with the blower in the air handler and the outside unit is shutting down on compressor protection.

You'll need to check the blower for proper operation.

 

PJmax, I did some tests last night. I switch the fan to on, when the blower is not running, it wouldn't start, though I can hear the switch in the thermostat click. I switch the fan to on, when the blower is running, it stops as the switch is in off position.

Does this sound like a control board problem? The fan will run, just don't know when. It's unpredictable. Is there a temperature sensor in the blower unit that will turn the blower on if it's overheat in the chamber?

Thanks