+1 408-878-6810
We help if

Heat pump outdoor coil freeze ups

Issue description:

When is the freezing of the pipes of the outdoor unit of the air conditioner not a breakdown?

Turning on the air conditioner for the first time after winter. The pipes often freeze up when the split system is first started after a long idle time. Let the air conditioner run for an hour or two. Perhaps the tubes will thaw and no longer freeze.

A light layer of frost on the tubes. Suppose, if the split-system is working properly in all modes and there is no "fur coat" in the outdoor unit. A small layer of frost turns into weak condensation on the pipes during the "rest" of the air conditioner.

If you see a lot of ice in the outdoor unit, or the presence of frost on the pipes is combined with poor cooling of the air conditioner - most likely, this is a breakdown.

Reasons why the thick tube of the air conditioner freezes up:

The gas tube of the external unit of the split system is frozen

Ice on the thick tube of the external unit of the air conditioner and its nut is due to the fact that the cooling process continues after the indoor unit. This is because the refrigerant does not completely boil off in the evaporator. "Boiling" occurs in the suction tube of the compressor, which is why it freezes.

Quite often, the reason lies not in a breakdown, but in an incorrect installation, incorrect maintenance or unprofessional repair of the air conditioner. The most common installation, maintenance and repair errors that cause the gas pipe to freeze include:

Excessive refrigerant. If too much freon is poured into the split-system during installation or refueling, it will boil not only in the evaporator, but also in the thick tube.

Short route. Each manufacturer of air conditioners prescribes the permissible length of the route in the instructions. If it was shortened during installation, this will also lead to freezing of the low pressure pipe.

Hall of a thick pipe. Sometimes the tube is bent during the "handicraft" installation of air conditioners. This leads to a disturbance in the circulation of freon, as a result, it partially boils in the gas tube, and you see ice on it.

If the air conditioner worked normally before, it was not refilled, and the ice began to appear on the thick tube - a breakdown occurred.

Heat pump outdoor coil freeze ups


Dirt in the indoor unit of the split system. Due to the accumulated dust and dirt, heat exchange is reduced, which leads to improper operation of the air conditioner.

Dirt of the outdoor unit. A large amount of dirt and dust impairs the heat exchange of the outdoor unit with the environment and lead to improper operation of the split system.

Faulty fan of the indoor unit. It spins only at low speeds or does not work at all. The heat exchange in the split-system is disrupted, and ice forms in the indoor unit and on the thick low-pressure tube.

The thermostatic expansion valve / ERV valve is faulty or its settings are out of order (for complex split systems). The thermostatic expansion valve or electronic expansion valve does not create enough differential pressure to boil off the refrigerant in the evaporator. As a result, the freon "boils" in the gas tube, which leads to its freezing. If you need help with affordable heat pump repair, call us right now!