Maintaining your Air Handler

We’ve discussed the air handler and its function as part of your HVAC system. Now, let’s talk about some aspects of maintenance for this important system component. Professional service is highly recommended, as this is a pretty technical piece of equipment. We can come out as part of scheduled maintenance visits to check your air handler.

Spring maintenance checks can help you avoid costly A/C repairs when the heat of summer arrives. Air handling units have high voltage running into them and there is a shock hazard. So, remember that only an HVAC professional should work on the air handler unit.

Inside the unit are the evaporator, metering device (on most units), the blower motor, and some electro-mechanical controls for HVAC control. The metering device and the electro-mechanical controls should be checked by an HVAC professional to ensure that they are clean and functioning properly.

A big problem people encounter with the evaporator coils is blocked coils. Usually, this means that the coils are plugged with dust, dirt, and other debris. For the evaporator to work properly and efficiently, the coils must be clean and have a measured amount of air flow.

This is one reason that a good filter is necessary, in order to filter all the particles from the air before it reaches the coils. If the air is not filtered, then there will be a build-up over time of dust and debris that get sucked into the return. This build-up clogs the evaporator coil and can actually cause the coil to ice up. The air handling unit becomes less and less efficient and will eventually fail to cool or heat the home. Air handling units need basic preventive maintenance to prevent premature breakdowns and to keep them operating at peak efficiency.

Cleaning the coils is also an important part of air handler maintenance. Coils operate below the dew point when the air conditioner or heat pump cooling cycle is on. This will make the evaporator coil wet, so when the dust makes contact with the coil it will often stick to it. Over time this will cause a build up and eventually the HVAC system will stop cooling. With improper flow across the evaporator coils there is no heat exchange process. The coils will freeze and ice will form on them. Another cause of ice forming on the evaporator coil is a low refrigerant charge. If the evaporator coils are clean and they are icing up, you need to call an HVAC professional to check the refrigerant charge.

Typically the only required HVAC maintenance on the blower is oiling the air handler blower motor if it has oil ports, or checking the belt if you have a belt driven motor. Not all blower motors have oil ports. These blower motors use sealed bearings and never require oil. The air handler blower motors that do have oil ports usually have little plastic dust caps that can be removed so that oil can be applied.

Clean coils, a working motor, proper filters and refrigerant levels and good air flow are essential elements for the efficient operation of your air handler. If you suspect that your air handler isn’t doing its job, let us know. With regular maintenance, you can get the best performance out of this critical piece of HVAC equipment.

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