Labor Day weekend in Wayne County usually hands you both seasons in one day. It is 48 degrees when you let the dog out in the morning, and by the time the grill is going the windows are open again. The furnace has not run since April, and it will not have to for another six weeks before you really need to turn it on.
That gap is the reason to work through a fall heating maintenance checklist now. Five items on it you can do yourself, in an afternoon, with nothing more specialized than a step stool. Doing them in September rather than on the first truly frigid night is the difference between finding a problem and having one.
1. Change the filter, and get the MERV rating right
Start with the filter, because it affects everything else. A loaded filter starves the blower, and a starved blower makes a furnace run hot. MERV is the number printed on the frame: Minimum Efficiency Reporting Value, a scale of how much fine airborne material a filter captures.
The EPA’s guidance is to select a filter rated at least MERV 13, or as high as your system will accommodate. Department of Energy testing puts MERV 8 at better than 20 percent capture of particles in the 0.3 to 1.0 micron range, and MERV 13 at better than 50 percent.
The second half of that EPA sentence does quiet, important work. Pushing air through denser media costs pressure, and excessive pressure drop can overheat a furnace, freeze an air conditioning coil, or burn out a blower motor. Thickness decides whether that happens. A 4-inch MERV-12 filter typically runs 0.2 to 0.35 inches of water column, comfortably inside residential guidelines, while a 1-inch high-MERV filter is far more likely to cause problems. An older PSC blower motor simply loses airflow. A variable-speed motor compensates by working harder and drawing more power.
So with a 1-inch slot, a mid-range pleated filter is often the honest answer. With a 4-inch cabinet, MERV 13 is realistic. The EPA itself says to check with a professional like Buselli Solutions if you aren’t sure what your system truly needs in terms of filters.
2. Walk the house and uncover every vent and return
Do a lap of the house and look at every grille in it. Things migrate over the summer. A couch gets nudged over a floor register, a rug covers another, and the spare bedroom collects boxes stacked against the return.
Your system has two kinds of openings, and people forget the second. Supply registers push conditioned air out. Return grilles are how the blower gets air back, and they are larger, fewer and easier to block. A blocked return does to your furnace what a clogged filter does, and nothing about it looks broken.
Reopen anything you closed off last spring while you are at it, and vacuum out the floor ducts. Did you know closing vents does not redirect heat somewhere useful? It actually raises duct pressure and pushes more air out through leaks.
3. Clear the space around the furnace
Give the furnace three feet of clear floor on every side you can, and move the flammable things out of the room. Basements and utility closets fill up over the summer without anyone deciding to fill them.
Move the paint cans, the gas can for the mower, the cardboard, the bag of grass seed. A furnace that burns fuel needs combustion air, and the room it stands in is where that air comes from. Boxes against the cabinet also mean a technician has to unload your basement before opening a panel.
Then go outside and look at the vent. High-efficiency furnaces vent through white PVC pipes at the wall, and mud daubers are enthusiastic about those over the summer. Older systems vent into a chimney, worth a look for a nest. Keep that vent in mind once weather turns, because the Consumer Product Safety Commission specifically recommends clearing snow away from fuel-burning appliance vents.
4. Test the thermostat and change its batteries
Change the batteries in September, whether or not the thermostat has complained. A dying thermostat battery is one of the most common reasons a furnace appears dead on a cold morning, and it is a two-minute fix people pay a service call to discover.
Pull the cover while you are there. Corroded terminals, a wire backed out of its screw, or a thermostat sitting in afternoon sun all cause comfort complaints that have nothing to do with the furnace.
If yours is programmable, its schedule is still set for summer. Build the heating schedule you actually want now, overnight setback included. Then check that the system switch is on Heat and the fan is on Auto rather than On. Fan set to On runs the blower continuously, and people mistake that for a furnace that never shuts off.
5. Run the heat for fifteen minutes while it is still warm out
This is the item people skip, and it is the one that actually tells you something. Pick a mild afternoon, open a couple of windows, push the thermostat up until the burners light, and stand there for a full cycle.
You will probably smell something, and that is normal. Dust settles on the heat exchanger all summer and burns off the first time the metal gets hot, and it usually fades within a cycle or two. What is not normal is a burning smell that persists, a hot plastic odor, or the sulfur smell added to propane and natural gas. That last one means you leave the house and call from outside.
Listen to the order of operations too. The inducer spins up, the igniter glows, the burners light with a soft whoosh, and the blower follows. Anything harsh in that sequence, or a lazy yellow flame instead of a crisp blue one, is covered in seven furnace problems worth catching early.
What a fall heating maintenance checklist can't catch
Everything above is airflow, housekeeping and controls. None of it touches combustion, and combustion is where the safety-critical items live.
You cannot reasonably inspect a heat exchanger for cracks, measure gas pressure, run a combustion analysis, clean a flame sensor, or confirm the rollout and limit safeties actually trip. Those are the substance of a fall heating service visit.
So here is the honest version. If your furnace ran without complaint last winter and all five items check out clean, we still suggest an HVAC maintenance before the cold season hits. Having a professional inspect your system is preventative and often required in order to keep your warranty. Call Buselli Solutions to schedule your HVAC maintenance and ensure your system is ready for the inevitable long winter ahead.
Frequently Asked Questions
- How often should I change my furnace filter? Look at it monthly during the heating season rather than following a calendar. Pull it out, hold it up to a light, and change it when the media is visibly loaded. A 1-inch filter loads up far faster than a 4-inch one, because it has much less surface area to hold dust.
- What MERV rating should I use in my furnace? The EPA recommends at least MERV 13, or as high as your system will accommodate, and that second clause matters. A 4-inch MERV-12 filter typically runs 0.2 to 0.35 inches of water column of pressure drop, within residential guidelines. A 1-inch high-MERV filter is far likelier to restrict airflow.
- Is the burning smell when I first turn on the heat dangerous? Usually not. It is summer dust on the heat exchanger burning off, and it typically fades within a cycle or two. Open a window and let it clear. A burning smell that lasts for days, a hot plastic odor, or the rotten-egg smell added to propane means you call from outside.
- Do I still need a professional tune-up if I do all five of these? They barely overlap. Your five items handle airflow, clearance and controls. A technician handles combustion: gas pressure, burner and flame sensor condition, heat exchanger inspection, draft, and whether the safeties actually shut the system down. This list buys you time. It does not replace the inspection.
Buselli Solutions — Here to Help You Get Ahead of Heating Season
That is the whole fall heating maintenance checklist: the filter and its MERV rating, the vents and returns, the space around the furnace, the thermostat and its batteries, and a test run while the weather is still forgiving. Work through it over the long weekend and you will know something real before you need it.
Buselli Solutions has been family-owned and working out of Honesdale since 1984, and our technicians spend the fall in basements across Wayne, Pike and Lackawanna counties finding what a homeowner checklist cannot reach. Our calendar fills fast after the first hard freeze, so early September is an easier time to get on it. If your test run turned up anything you did not like, book a fall tune-up.