Heat Pump Ice
- Thread starter jaxsunst
- Start date
Help Support :
toggleswitch2
Well-known member
- Joined
- May 23, 2008
- Messages
- 5,000
High winds and/or high humidity (i.e. its raining outside) may be a factor if the unit itseself is not defective or malfunctioning.
I found hot water is effective for defrosting.
Please note that one should not "hard-power down" power to the outdoor unit. There is a crankcase heater that keeps the oil (and refrigerant?) warm in the compressor (in cold weather), to prevent damage.
Issues may be a defective defrost timer, a "lockout" control that does NOT stop the outdoor unit's fan when defrosting or even a low refrigerant level.
Some units have an expansion valve indoors just before the indoor coil. If going bad, may contribute to such issues. If this is the case, please consider hiring a firm that does commercial applications. Many "residetnial service" guys just don't know how to deal with one.
Good luck.
I found hot water is effective for defrosting.
Please note that one should not "hard-power down" power to the outdoor unit. There is a crankcase heater that keeps the oil (and refrigerant?) warm in the compressor (in cold weather), to prevent damage.
Issues may be a defective defrost timer, a "lockout" control that does NOT stop the outdoor unit's fan when defrosting or even a low refrigerant level.
Some units have an expansion valve indoors just before the indoor coil. If going bad, may contribute to such issues. If this is the case, please consider hiring a firm that does commercial applications. Many "residetnial service" guys just don't know how to deal with one.
Good luck.
This is your first experience with a heat pump, yes? Ice is completely normal under some weather conditions (high humidity/moisture, mist/light rain, near-freezing or below outdoor temps). Just like a freezer/refrigerator evaporator ices-up, so does a heat pump (outdoor) condenser when it's operating as an evaporator in heating mode. Assuming the unit is operating correctly, defrost will trigger to melt off the ice. During defrost, the unit switches to air conditioning mode so the outdoor coils again function as a condenser and get warm. The auxiliary electric heat strips in the air handler activate to counteract the cold air that would otherwise be blowing in the house (but the heat strips have nothing directly to do with defrosting).
The Lennox at my previous house frosted-up in February of 2003.
The Lennox at my previous house frosted-up in February of 2003.
Carrier at the current house, January 2007.
Defrost in-progress.
Finished. The outdoor fan turns off during defrost and it's not unusual for moisture/steam to billow from the unit. Notice the puff of steam in this picture blowing out when the fan turned on at the end of defrost. People not familiar with what's happening have called the fire department in alarm, thinking their unit is smoking/on fire.
Glenn, your pictures are exactly what it is doing. Thanks, I feel better about it.
Steve, I turned it off at the thermostat. It does a delay before actually stopping. I was warned by the guy that installed it to never turn it off at the breaker, he said to turn it off at the thermostat and wait 2-5 minutes before shutting off the breaker.
Steve, I turned it off at the thermostat. It does a delay before actually stopping. I was warned by the guy that installed it to never turn it off at the breaker, he said to turn it off at the thermostat and wait 2-5 minutes before shutting off the breaker.
This raises another good point. If the electricity fails at your home during cool weather (cool enough you need to run it on heat) make sure you turn the switch on your thermostat to OFF during the power failure.
If the electricity were to come back on, the thermostat will call for heat immediately and the system will start up without letting the crankcase heater do it's job. Under extreme conditions, this could lock up the compressor motor and destroy it. The least it will do is trip the breaker when the motor overloads.
Make sure to let your unit sit with the thermostat in the "OFF" positions (but with all the breakers or fuses installed) for about an hour or so before starting it back up.
If the electricity were to come back on, the thermostat will call for heat immediately and the system will start up without letting the crankcase heater do it's job. Under extreme conditions, this could lock up the compressor motor and destroy it. The least it will do is trip the breaker when the motor overloads.
Make sure to let your unit sit with the thermostat in the "OFF" positions (but with all the breakers or fuses installed) for about an hour or so before starting it back up.
