June 15, 2015

Signs an HVAC System Needs a Check Up

dusty vent cleaningTalk about high maintenance! With most HVAC systems in continual service, be it heating throughout the winter or cooling in the summer, pay attention to these warning signs. Remember that wall caps, soffit vents, grilles and roof vents are exposed to weather extremes and might need some care as well.

Temperature check

One sign an HVAC system needs maintenance is decreased efficiency. Ideally, there’s a uniform temperature throughout the house or building. If you notice wide variations this could mean problems with the ductwork. If possible, do a visual check as well as run the system and feel along the ducts to find leaks. Then think about this: According to the U.S. Department of Energy’s Energy Star program, leaky ducts in attics or crawlspaces can account for 20% or more of a home’s heating and cooling energy losses.

Traffic jam

Another potential problem could be dust, fibers and debris that partially block the ductwork and furnace filter. Make sure the filter is replaced regularly but if it needs this too often it could be a sign that dirt is getting sucked into the system.

In the past, ductwork was often just screwed together without tape or sealant. Even if it was wrapped with regular, fabric-backed duct tape, this will deteriorate over time. Use a foil tape or mastic sealant at all the connections in the ductwork, including where the ducts attach to the registers.

Don’t forget to check the dryer vents – these are often blocked with lint that can create a fire hazard and other exhaust vents can also clog with grease and dirt.

Allergies = mold

While you’re at it consider insulating the ducts especially in the attic or crawlspace where cool air can cause heat loss and condensation problems. Mold will grow in the presence of moisture and is terrible for our health. Once it’s in the ducts, it will be blown throughout the house and possibly cause allergic reactions and respiratory problems.

If dirt or mold gets into the forced air system it will be necessary to get the duct work cleaned. Some contractors use powerful vacuums but a better method includes running a spinning probe that whips the encrusted dirt from the inside walls of the ducts. Some services include spraying the walls with a disinfectant to remove mold, viruses and bacteria.


Remember all the other components of the HVAC system. Roof vents in particular are hard to see and easy to forget about. Get up on a ladder and do a visual inspection. Metal vents are susceptible to damage from hail and snow. Check for deteriorated vents and make sure dampers and screens are in place and working correctly. Consider replacing with the more durable plastic type that are dent and UV-resistant.

Birds and other animals will sometimes nest in the vents if there is no screen but in the case of larger critters screens may get ripped out or even the entire vent taken off.

Proper attic ventilation is dependent on the soffit grilles or vents. These are also susceptible to damage from animals and are a favorite location for wasps and bees to make nests. Blockage of these will prevent air circulation into the attic, which can lead to ice dams in the winter and hot roofs in the summer.

Not only will proactive maintenance prevent costly repairs down the road but a check up will lead to increased energy savings from better efficiency.

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