System Maintenance Checks When Switching from AC to Heat this Fall

Summer weather’s coming to an end across the U.S. In Chicagoland, highs in the 70s and 80s are starting to dip into the 60s. Winter is on its way, and the Farmer’s Almanac is predicting a cold, snowy season.

As you switch from AC to heat this fall, what should you watch for? A rapid transition from AC to heat requires a bit more attention to make sure everything is running normally. When you check a few things before a cold snap hits, you often save money, protect everyone in your home from health risks, and, most importantly, avoid mid-winter breakdowns.

The last thing any homeowner wants is to be stuck with no heat on a bitter cold day. Air Blue Heating and Coolin g has a checklist of system maintenance checks to complete before fall arrives. We recommend hiring a professional, as many cleaning and inspections are best left to a licensed professional for your safety.

The AC to Heat Transition

Before moving from cooling to heat, check the thermostat and system responsiveness.

Replace Batteries: If your thermostat uses batteries, start the season by changing them. A weak or dead battery will impact your system.
Switch System Mode: Switch your thermostat from “Cool” to “Heat.” Set the temperature a few degrees higher than the current room temperature to force the heating system to kick on. Make sure the room is quiet.
Verify That the System Starts: As the heating system turns on, listen for it. Pay attention to any noises that don’t seem normal. After a few minutes, check the supply vents in different areas and make sure you feel warm air.
Review Schedules: Whether it’s on the programmable thermostat or in an app, adjust your thermostat schedule to match fall schedules. It often gets dark earlier, so sleep schedules often shift.

Air Filter Inspection

A heating system relies on proper airflow. Restricted airflow increases the risk of emergency shutdowns due to overheating or cracked heat exchangers.

Remove the Filter: Summer’s pollen and dust build up fast as your AC runs. Remove the filter from your system and inspect it. If you hold it up to the light and cannot see through it, replace it. Ideally, change a filter before it becomes extremely dirty and clogged.
Install the Correct Filter: Air filters have a MERV (Minimum Efficiency Reporting Value) rating. The higher the number, the more particles it traps. This may seem beneficial, but not every HVAC system’s blower motor can handle a high-MERV filter. It can strain the motor and lead to an unexpected breakdown.
Pay Attention to the Arrows: When you’re inserting the new filter, make sure you position it correctly. Use the arrows to ensure the side facing the blower motor is correct.

Outdoor Air Conditioner Clean-Up and Protection

As you move into the heating season, take steps to protect your outdoor condensing unit for winter. Because these checks can affect your system’s lifespan and your safety, hire a professional HVAC technician to perform these yearly cleaning and inspection tasks. It’s not something you should do on your own.

Turn Off the Outdoor Unit: To keep your AC from kicking on during a warmer, sunnier winter day, turn off the switch for the condenser unit outside.
Remove Fallen Leaves and Debris: As fall foliage makes way for dormant trees all winter, leaves can build up and block vents on outdoor condenser units, trapping moisture. Keep them from decomposing during the winter and getting stuck in vents. Remove them all before the snow falls.
Inspect Coils and Fins: Visually inspect the exterior condenser coils for dirt accumulation or bent aluminum fins. Use a garden hose to remove any grime. A fin comb can straighten bent fins. Hire an air conditioning technician to complete a full cleaning before winter arrives.
Apply a Protective Cover: If your AC installer recommends it, a breathable cover or wood board placed over the top of the unit can keep ice or snow from getting into the vents.

Furnace Interior and Blower Compartment Maintenance

Dust buildup in the furnace cabinet can create a distinct burnt smell when the heating system fires up for the first time. It’s important to clean out any cobwebs, dust, or pet fur that’s gotten in. Turn off the power at the breaker and shut off the gas supply before cleaning anything.

Clean Dust and Debris: Open the access doors to the heating system and use a soft upholstery brush attachment on a vacuum to remove any dust or debris.
Inspect the Blower Fan Blades: Look at the fan blades and make sure they’re clear of dust, hair, and cobwebs.
Check Belts and Bearings: If you have an older heating system with a belt-driven blower, check the belt for cracks, frayed areas, or looseness. If the belt is about to break or too loose to turn the fan, you’re going to have issues.
Look for Chemicals Within Three Feet: Don’t store household cleaners, paint cans, or other flammable materials near your heating system. Make sure they’re more than three feet away.

Burner, Flame Sensor, and Ignition Inspection

A correct balance of oxygen and gas is needed for pilot light and burner ignition and safe operation. Technicians complete these steps to ensure your system works correctly.

Inspect the Burners: Technicians look for blockages, corrosion, and rust, which can affect ignition and combustion.
Clean the Flame Sensor: The flame sensor is a thin metal rod located within the burner flame. Over time, oxidation builds up on this rod, preventing it from detecting the flame. If it can’t detect a flame, it will shut down the furnace right after it lights. Remove this sensor and clean it before reinstalling it. Older systems may use thermocouples instead, which must be replaced.
Inspect the Hot Surface Igniter or Pilot Assembly: Modern electronic ignition systems use a hot surface igniter. Technicians look for cracks or dark areas that indicate wear and part failure. Older systems using a pilot light must have the pilot assembly inspected for debris and cracks.

Heat Exchanger and Flue Vent Safety Checks

A heat exchanger separates gases created during combustion. One of those gases is carbon monoxide, which can be deadly if it builds up within your home. Technicians carefully inspect and test flues and heat exchangers to ensure carbon monoxide vents properly.

Heat Exchanger Inspection: Using a flashlight, an HVAC technician looks at all visible areas of a heat exchanger for cracks, rust, soot, and gaps in the metal. Heavy soot buildup can indicate incomplete combustion.
Examine the Draft Inducer Assembly: The fan wheel in the draft needs to move freely without making unusual noises or scraping against other components.
Check the Flue Pipe: Joints must be tightly connected and sealed. No rust should be visible, and the pipes shouldn’t sag or come apart. At the vent pipe exit, leaves or bird or mouse nests shouldn’t block the opening.

Ductwork and Supply Vents

An efficient furnace needs ductwork and supply vents in good condition. They cannot be obstructed by drapes or furniture or damaged by rodents or animals that got into your home.

Inspect All Registers and Vents: Check every room in your home to ensure supply registers and return air grilles aren’t blocked by furnishings. Closing vents in rooms you don’t use often can affect static pressure and increase the risk of an overheating system. They must be left open.
Clean Return Grilles: Use a vacuum nozzle to remove pet fur, human hair, and other debris from return grilles. This also helps keep particles from clogging your air filter as quickly as they otherwise would.
Inspect Accessible Ductwork: Check all ductwork that is easily accessible in your basement, closets, or attic. Look for cracks, tears, or any reason you might need repairs to your ducts. Run your hand along joints and see if you feel any air leaks. Use metal tape or mastic sealant to seal joints that are starting to separate.

CO2 and Smoke/Fire Detector Usage

Heating systems involve high temperatures, making functional home safety devices essential before you turn on the heat this season. Make sure you have smoke/fire detectors in bedrooms and on every floor of your home.

Carbon monoxide detectors are also essential on each floor and in each bedroom. If they’re already installed, test them. It’s also a good time to change batteries.

Full Operational Run and Inspection

All inspections and cleaning tasks are complete. Now it’s time for the HVAC technician to start the system and do a final inspection.

With three locations, we cover a lot of Chicagoland and its surrounding suburbs. From Waukegan in the north to Oswego in the south, our service area is substantial. Text or call (847) 450-7366 to schedule a professional HVAC cleaning and know that your system is ready for whatever winter brings.