HVAC Repair – How To Properly Clean Your HVAC System

Your heating, ventilating, and air conditioning (HVAC) system provides a comfortable living environment by controlling the indoor temperature, air quality, and to some degree, humidity. If your system includes both a heating and air conditioning subsystem, much of the equipment is performing double-duty. Periodic maintenance is necessary for your system to work correctly throughout the year. Performing just a few simple procedures on a regular basis can help you avoid unnecessary — and very costly — repair service bills.

Of course, some of your HVAC system’s components wear out from time to time, such as the blower fan, heating elements, and air conditioning compressor unit. These are things you can’t fix without professional help. However, smaller tasks you can perform yourself should never be overlooked. The following procedural steps will help you design a regular maintenance schedule.

Air Filters

These are located near the base of the heating or air conditioning unit. On units that contain air conditioning evaporator coils, they’re usually placed diagonally below the coils. Most of the old-style, rather cheap filters need to be replaced about once per month. However, it’s suggested that you invest a couple more dollars and get the new high-efficiency pleated filters. These filters hold an electrostatic charge that traps even the smallest hairs and dust particles. They only need replacing about once every three or four months.

While replacing the air filters, make sure you use a damp cloth and a grease cleaner to get the grime off of the fan motor and the areas where wiring sockets plugin. Remember to turn off the unit and shut off the breaker circuit before you do this, and after wiping down the surfaces, wipe again with a dry cloth to get them completely dry before turning the unit back on.

Duct Cleaning

This sounds like a really nasty and time-consuming procedure, but if you follow the following steps in the correct order, you’ll find that cleaning out your ducts is a snap. You’ll need a vacuum or shop vac, a handheld dust brush, screwdrivers, and cleaning cloths.

Use some of the cloths to cover your supply registers. These are the registers where the cool or warm air comes out. Lift up the grills and place the cloth on top, and then close the grill. Turn on the fan unit, but keep the heat turned off. Lift one register and sweep out the collected dirt and dust. Repeat with each register in the house.

Unscrew the return registers. These are the smaller registers that allow air to return from the indoor environment. Reach in with the vacuum or dust brush to get at the dirt that collects at the start of the return piping.

Locate the air duct covers and unscrew the fastenings. After removing the cover, use the vacuum cleaner to clear out dirt and dust in the flow pipes. If your vacuum isn’t powerful enough, rent one from a home improvement center.

If your system has a separate furnace filter, one that is located in an area where the air is drawn into the system, you’ll need to replace it after cleaning your ducts.

Preventing Mold And Mildew

During the summer, your HVAC system cools the air that’s drawn into the evaporator coils. This causes condensation and an eventual buildup in the drain pan. Make sure you check the pan several times during the summer to see if water and debris are clogging the drain. This is important because most systems have a float valve that automatically shuts down the system if the water can’t drain out.

A buildup of condensation can also dampen any hairs or dirt particles that are caught in the evaporator coil slivers. The wetter these become, the more difficult it is for the AC to work properly because the air doesn’t get cold enough. “You can’t clean the evaporator coils yourself because the work involves draining the refrigerant, something only a licensed professional can do,” says the guys at FurnaceUSA in Austin. This is very costly, so make sure you gently scrape away any pet hair buildup or other fibers from the coils each time you change the filters. Another neat trick is to pour a cup of bleach dissolved in a quart of water into your drain pan. This will help prevent clogs from forming further down the drainpipe.

These steps will prevent mold and mildew from building up as well. The last thing you want is mold and other unwanted organics moving through your system, out of the registers, and into your living area. You can also check out online resources for how to install a UV lamp next to your air handler and blower fan unit. The blue light prevents mold from growing.

Humidifiers And Dehumidifiers

If your furnace unit has a humidifier, shut it off during the summer months or at least shut off the water supply. In the fall, when it’s time to start using your furnace again, replace the humidifier wick filter. Reset the humidistat to 35 percent. This is usually a bit lower than the average humidity inside the home during the winter months. Remember to turn the water supply back on at this time!

Condenser Units

You can go ahead and shut down the circuit to the outdoor air conditioning condenser unit in the fall. Most homes have circuitry that separates the 24-volt charge sent to the thermostat, so the AC circuit doesn’t have to be in the “On’ position if the cooling system is not in use. It’s a good idea to purchase or construct a cover for the outdoor unit. This keeps leaves and other debris from getting into the system between fall and spring.

Remember to check the insulation on the refrigerant line periodically, even during the winter months, when the cooling system isn’t being used. If the insulation is coming loose or is worn, replace it immediately. Don’t wait until spring; otherwise, you might find that your refrigerant was warmed and “burned out.”

Commonly Overlooked Procedures

If you know where the moving parts are located and where to oil them, be sure to do this several times per year. If a problem develops with the electrical, you can use a multimeter to check resistance on the ends of the wires at the thermostat end. If your thermostat has a battery backup, turn off the system at the breaker panel and see if the display is still working. If it’s not, and you can’t get any heat, make sure the red and green wires still have a 24-volt charge and that the thermostat switch will still turn on the blower fan. If it does, you have a damaged thermostat, and you’ll want to replace it promptly before you need to use the heater unit.

These are just a few steps you can take to perform preventative or repair maintenance of your HVAC system. A few hours per year are worth it, especially when you consider the hundreds of dollars you’ll spend on a visit from a professional. Consider also the cost of upwards of $1,000 to have your evaporator coils cleaned or what it might cost if your gas or electric heater unit has to work overtime. Your HVAC system will perform trouble-free for much longer if you follow the steps mentioned here. The savings are certainly worth it!