What Causes the Suction Line to Freeze Up?

Refrigerants have two copper lines that connect the indoor evaporator coil and the outdoor heat pump. The suction line is the larger tube that has insulation. It carries cool gas under low pressure from the indoor evaporator to the outdoor compressor. The suction line is also called the return or the vapor line.

The other line is usually smaller and uninsulated. It carries hot liquid under high pressure from the condenser to the evaporator.

The suction line can freeze for many reasons. Read on to know the main ones.

Airflow Problems

If the filter gets dirty, it blocks airflow to the evaporator coil. Without airflow, heat doesn’t get to the evaporator coil, and the refrigerant doesn’t boil. As a result, the pressure and the temperature will drop, causing the system to freeze.

If the filter you’re using is too restrictive, it can cause the same problem. In this case, you’d have to replace the filter.

Also, the blower motor could stop working or run at a low speed due to worn-out bearings. An electric problem could blow up the motor, or the board could fail to supply current. This problem reduces the amount of air getting to the evaporator coil. The longer you let the system work without the motor, the more ice will accumulate on the suction line. Anything that blocks airflow to the evaporator coil can cause the unit to freeze.

Low Refrigerant

A refrigerant is a compound that changes from gas to liquid and vice versa as it regulates temperature in the house. When the refrigerant absorbs heat from the house, it changes from low-pressure gas to high-pressure liquid. Then the high-pressure liquid travels outdoors where a fan blows hot air. As a result, it turns back into a low-pressure gas.

The refrigerant’s volume remains at the same level throughout the HVAC professional in Santa Fereach out to James Plumbing & Heating. We can help with inspection, cleaning, maintenance, and even replacement of the system. Feel free to contact us for questions, consultations, or appointments.