Common Heat Pump & Air Conditioner Problems

These very common heat pump and air conditioner problems can be easily dealt with by calling your local experienced HVAC technician at LHT Cooling, Heating and Refrigeration, Inc.

Unit won’t heat/cool without electric or other backup:

• The compressor is not running
• Short or out of refrigerant
• Reversing valve is stuck in cooling mode or halfway
• No power to the unit
• Pressure controls are tripped

Do not replace these components without first having a licensed technician diagnose them.

Unit won’t heat well – can’t keep up with thermostat:

• Unit is over/under charged
• Unit is undersized for job
• Metering device problems
• Poor air flow (discharge will be hot and you will hear pulses from compressor in refrigerant line
• Indoor coils dirty (head pressure will be high)
• Outdoor coils dirty (suction pressure will be low)
• Compressor is weak (suctions pressure will be higher than normal)

In heat mode, a dirty coil will rob the efficiency and raise the head pressure.

Unit freezes or turns to block of ice:

• While it is totally normal for frost to accumulate during the defrost cycle, it is never normal for the entire unit to be encased in ice
• When defrosting you get a blast of cold air caused by electric heat not being activated – this is not a harmful malfunction – just an annoyance

If you have to continually reset unit:

• Unit is overcharged
• Filters are dirty
• Metering device is stuck

Outdoor or indoor unit will not shut off: outdoor unit will not shut off when thermostat is not calling for heating or cooling.

• Cut power and turn off immediately – call your local licensed technician at LHT Cooling, Heating and Refrigeration, Inc.

It’s always best to consult your local licensed HVAC technician for these common heat pump and air conditioner problems. Here at LHT, we are ready to help you.