Modern heating and cooling equipment is more reliable and efficient than ever before. Manufacturers continue to introduce improvements that enhance comfort and help lower power costs. However, furnaces and air conditioners frequently operate in severe weather conditions, and motors, relays and sensitive electronics are subjected to enormous stress and wear. An HVAC system is typically the largest appliance purchase a homeowner will ever make, so it is important to proactively address maintenance tasks to protect your investment.

An Easy DIY Maintenance Program

There are several aspects of furnace and AC maintenance that can be completed by the homeowner, but any services related to mechanical or electrical components should only be performed by a qualified HVAC contractor. An annual preseason tune-up includes a wide array of tests, inspections and calibrations that will expose hidden problems before they can affect system performance. Homeowners are advised to avoid making any unauthorized modifications to their heating and cooling system since such actions can void the warranty and permanently damage the equipment.

Change the Air Filters Regularly

Changing a disposable air filter is the easiest and most beneficial regular maintenance task a homeowner can perform. Central filters remove unhealthy contaminants from the living area and also keep vital internal HVAC components clean. When filters are clogged, the air flow is restricted, and the unit is forced to cycle longer to meet the indoor load. This lowers equipment efficiency and negatively affects indoor air quality. Accumulated runtime hours can eventually cause a breakdown and may lead to premature unit failure.

Before changing a filter, make sure the power to the appliance is disconnected. Filters are always located on the return side of the system, either inside the furnace cabinet or held in place by mounting brackets attached to a hinged return air grille. The old filter should slide out easily, and sizing information will be clearly stamped on one end of the frame. When installing a replacement filter, always make sure the airflow follows the printed arrow on the filter. Most HVAC contractors recommend installing a filter with a MERV rating of 7-9, but it is important to determine if the system has sufficient capacity to handle the additional friction loss. Disposable filters should be changed monthly, and cabinet media filters need to be replaced on a quarterly basis.

Removing Debris from the Condenser

The condensing unit plays a crucial role in the refrigeration process. Since it sits outdoors, the condenser is punished by seasonal weather throughout the year. The powerful fan removes heat from the coil, but dirt, leaves, dust and other debris collect around and inside the unit. This can block air movement and create a restriction, which will reduce your air conditioner’s efficiency. Always inspect the condensing unit twice a year, especially in late spring and late fall when plants, bushes and trees are shedding. Remove any debris that has accumulated around the outer grille of the unit. For better performance, create a buffer zone between the condenser and the surrounding vegetation.

Access to the inside of the condenser requires removing screws and lifting off the lid. The fan wires may not have enough slack to allow the lid to rest on the ground, so you may need an extra set of hands. A soft bristle bush is an effective tool for dislodging any debris that is jammed between the coil fins. Use a common garden hose to wash off surface dirt and residual debris. Finish the cleaning process by vacuuming the coil and the interior of the condenser completely. If you notice any bent or crushed coil fins, a special tool called a “fin comb” can be used to straighten them out.

Cleaning Supply and Return Registers

Furnace and air conditioning systems often operate under a negative pressure due to leaks in the ductwork and building perimeter. This allows dirt, dust and other irritants to enter the airstream. As the HVAC system cycles, layers of grime begin to build up on the louvers of the supply and return registers. Over time, this can cause an airflow restriction and contribute to poor indoor air quality.

For complete cleaning, all the supply registers should be taken down. This can be accomplished by removing the two screws that attach the register to the register box. A vacuum hose can be fed into the box to remove accumulated debris inside the ductwork. A medium brush is most effective at cleaning surface dirt off the registers, and a mild soap solution will dissolve caked on grime. Always take care not to scratch the paint on the registers and make sure they are firmly positioned in the register box before fastening the screws.

Clear the Condensate Drain

Water that puddles near the air handler is a sign of a clogged condensate drain line. If left unaddressed, unhealthy mold can begin to grow inside the air handler. Condensate pipes can be cleaned by carefully pushing a drain brush through the access port in the condensate line near the evaporator coil. Attaching a shop-vac where the pipe terminates can help suck out loose dirt and debris. If a restriction is encountered, stop the procedure and call a professional HVAC contractor.

Replace Refrigerant Line Insulation

Outdoor refrigerant lines are usually covered with rubber or foam insulation. The insulating value of these materials is often compromised by exposure to the sun’s UV rays as well as rain and snow. If the pipe insulation on your refrigerant lines feels hard and brittle, it needs to be replaced. Replacement insulation can be purchased at most hardware stores. The process of cutting off the old insulation and sliding the new sections on the pipe is relatively simple. While the old insulation may have been fastened with tape, using insulation glue to close the seams is recommended.

Spending a few hours every year tending to simple HVAC maintenance projects can save money in the long run. Your system will provide better comfort, cost less to operate and last longer than poorly maintained equipment.