Common Plumbing Repairs

Listed below are some of the more common repairs that we see throughout the year, and the causes that lead up to the part not working.

Refrigerant Metering Device

The Refrigerant Metering Device controls the flow of refrigerant through the air conditioning system much like a traffic light controls the flow of traffic down a street. All air conditioning systems will have at least one refrigerant metering device, and heat pumps will have two.

Much of a system’s efficiency is derived from the proper operation of this device. Too little refrigerant flow will cause the system to have reduced performance, and could cause the compressor to overheat. Too much refrigerant circulating though the system could overwhelm the compressor, causing damage. Often, a total failure of this component will result in the system not cooling or heating at all.

Reversing Valve

Reversing Valves are only found on electric heat pumps and are used to reverse the flow of refrigerant from the cooling mode to the heating mode and back again. They reside in the outdoor unit, and all of the system’s refrigerant flows through them.

The failure of a reversing valve can cause the system to stick in the heating or cooling mode. At times, the valve may fail in an intermediate position resulting in the system not working.

Any debris in the system can cause the reversing valve to fail. Also, normal wear of other components in the refrigerant system, or the failure of a compressor or other device, can cause the reversing valve to fail.


A restriction, or blockage, in the refrigerant system of a air conditioning unit can come in varying degrees. Screens, strainers or filters in the refrigerant system are installed in an effort to trap debris and prevent the failure of various components. However, large amounts of debris can result in a restriction, reducing the refrigerant flow through the system. A slight restriction may result in decreased performance. A larger restriction can result in the system not cooling or heating at all.

Indoor Coil

An Indoor Coil is a heat transfer device. The indoor coil absorbs the heat from the home’s indoor air, and passes it to the system’s refrigerant, which is then pumped outside.

As the air passes across the coil, any airborne dust or lint that collects on the coil reduces its ability to perform. Also, to provide the highest level of heat transfer, the metal used is extremely thin. Airborne chemicals, detergents and cleaners can start corrosion, resulting in leaks.

A coil in need of cleaning may have lower performance, or can ice up from the low airflow. A leaking indoor coil may operate for weeks, or even months, depending on the leak rate, but should be repaired or replaced to prevent further, more costly, damage. Leaks can occur in such locations that an attempted repair is not practical, and the entire unit may need to be replaced.

Outdoor Coil

An Outdoor Coil is a heat transfer device. The outdoor coil draws the outdoor air across the coil to absorb the heat from the refrigerant.

An outdoor coil should be cleaned periodically. Any dirt and dust in the air can be trapped on the coil and restrict its airflow and reduce its performance. They can also develop leaks from the constant vibration of the compressor, weakening the solder joints and tubing. The refrigerant is under very high pressures in the outdoor coil and even the smallest leak can result in a complete loss of the refrigerant charge. Any dirt and debris in the coil can increase these pressures straining the coil’s integrity.

Drain Lines

Drain Lines allow your air conditioning system to drain off the water it has condensed from the air. Over time the drain line can become blocked and cause the drain pan in the unit to overflow. Dust and dirt from the indoor coil can be washed into the drain line, where it settles and causes blockage. Unlike the failure of most other items in the system, a drain line failure can result in expensive water damage repairs.

Drain lines rarely give warning prior to becoming blocked and should be cleared annually.

Contact Us Today

Emergency Air LLC, 4360 W Chandler Blvd #1 Chandler, AZ 85226 - Phone: 602-400-0000

4360 W Chandler Blvd #1 Chandler, AZ 85226

Follow Us