Heat pump or Air Conditioner iced-up in summer:

It is never normal to see ice in the summer anywhere on a heat pump or central air conditioner. This includes the indoor unit, outdoor unit and interconnecting line-set. It is possible to ice-up the indoor coil however, if the air conditioner is running in very cold weather or if the thermostat is turned down extremely low.

We recommend never turning the thermostat below 70 degrees. If air conditioning is needed during winter months, such as for restaurants or businesses, then a "Low ambient kit" is required and can be installed by a service technician.

If you see ice on a heat pump or air conditioner in the summer there most likely is a problem. Below is a list of possible causes.

Bad indoor fan motor- not running/running slow
Loose, worn, or broken fan belt
Bad indoor fan relay
Clogged blower wheel
Low refrigerant charge
Restriction
Blocked capillary tube
Blocked orifice
Faulty expansion valve
Stuck compressor contactor
Faulty thermostat
Extremely dirty or damaged indoor coil
Clogged or blocked air filter
Supply and/or Return vents closed
Running air conditioner with windows open
Setting thermostat too low