My heat pump will run cooling mode for only about 30 min. or so. Then the outdoor unit shuts off. The indoor fan keep blowing. The smaller line going into the evaporator freezes between the evaporator and a valve with a capillairy tube that leads to the larger line. Once it thaws which takes about 20 min. the outdoor unit starts again. Temp in house never reaches 75 which is what it's set too. When it runs it does blow nice and cool I just need it to run longer.

Thanks
Phil

The low pressure switch is opening the circuit as a safety. You are low on refrigerant or you have a restriction in air flow= dirty: filters,blower wheel, evaporator coil, restriction at metering device at evaporator coil and or a bad blower motor.

My heat pump will run cooling mode for only about 30 min. or so. then the outdoor unit shuts off. the indoor fan keep blowing. the smaller line going into the evaporator freezes between the evaporator and a valve with a capillairy tube that leads to the larger line. once it thaws which takes about 20 min. the outdoor unit starts again. temp in house never reaches 75 which is what it's set too. when it runs it does blow nice and cool I just need it to run longer.

Thanks
Phil
Thank you for your help. My filter is new. I will check the blower wheel and evaporator coil. If that does not fix my problem I will call a tech to check if the system is low. It was low last year but he could not find a leak. If it is low again I guess they will have to look harder. :)

Thanks
Phil

If it was low last year and the leak was not fixed it will be low this year. If they can't find the leak have them add dye to the system, it won't lie it will tell you exactly the place of the refrigerant leak.

Service tech checked pressure said it looked fine then it started to drop after about 15 min. of running. The coil froze and the system shut down do to low pressure. The tech cycled the rev valve a couple of time saying it might not be fully seated in cooling mode. It ran for 45 min, then after he left it froze again starting at the coil and moving out to the Thermostatic expansion valve. Then the system shut down again. I'll have to call them back out again, but I'd rater not. $$$$ any other ideas for me to check before I whip the ol' pocket book?
Thanks
Phil

Yea call him back. He did not fix it the first time so the service call should be free.