There are several things that can cause your HVAC system to freeze up. Most need to be corrected by Mainline’s service center.
Making sure the filter is clean or replaced and making sure the airflow is not restricted are about the only things you can check or handle yourself.
Low refrigerant: In some cases, freezing up is caused by a leak in the refrigerant lines. Weak solder joints, friction from piping rubbing or vibrating against an object, leaking valves or loose fittings can cause leaks. The age of the system and the nature and location of the leak are the determining factors on whether to have the system repaired or replaced.
Dirty evaporator coil: Over time, the evaporator coil will become dirty. When this happens, the results are similar to those of having a dirty filter. Gradually you will lose airflow, slowly enough that you probably would not realize it until it freezes up or is not cooling adequately. You will need to contact Mainline’s service center to correct the problem.
Defective blower motor or relay: A blower motor not running at the proper speed or not running at all can cause freezing. It can also be intermittent, starting at full speed and slowing down after it heats up. Or a relay could cause it to start one time and not the next. In either case, you will need to contact Mainline’s service center to correct the problem.
Should you find that your system was freezing due to a dirty filter, after replacing or cleaning the filter, you can speed up the thawing process by turning the system off and turning on the fan. If you have a heat pump system, you can try turning the system to heating mode until the ice has melted. After the ice has melted, switch the system settings back to normal. If the system refreezes, contact Mainline Heating’s service center to correct the problem.