Heat Pump pressure issues

CardinalCory

I have a Ducane split system heat pump. Recently the outside unit wasn't kicking on. I took a look at it and the LED status indicators showed it was in high pressure lockout. I had a repair guy come and look at it. He reset the system and checked for possible caused but the system seemed to run fine after he reset it and he couldn't figure out the problem. The system continued to run fine for another 2 days and then the outside unit quit running again. I went out to check it out and the LED status indicator lights showed that it had a low pressure lockout.

Could you tell me what could be wrong with the unit that would cause it to first show high pressure lockout and then low pressure lockout?

Thanks for any help you can provide

Eugene_Silberstein

Sounds like an airflow problem

This sounds like an airflow problem.



If the airflow through the indoor coil is restricted for any reason, the high side pressure will be high when the system is operating in the heating mode and the low side pressure will be low when the unit goes into defrost. Possible causes for an indoor airflow restriction include dirty air filters, dirty indoor coil, closed supply registers, defective fan motor, loose belt, dirty blower wheel and loose duct lining.



If the airflow through the outdoor coil is restricted for any reason, the high side pressure will be high when the system is operating in the defrost mode and the low side pressure will be low when the unit is operating in the heating mode. Possible causes for an outdoor airflow restriction include dirty outdoor coil, defective fan motor, loose or damaged fan blade.



Hope this helps!



Good luck