Spokane’s first hard freeze always arrives faster than expected. Here’s the exact pre-season checklist to run through before you’re relying on your furnace every day — and what to schedule now instead of in November.
Late August still feels like summer in Spokane, which is exactly why this is the right week to think about your furnace. By the time the first real cold snap hits — and in this region, that can happen abruptly in October — every HVAC company in the Inland Northwest is booked out, and a furnace that’s been quietly failing all summer picks the worst possible week to actually quit. Here’s the checklist we’d run through on our own homes before the season turns.
1. Replace the Air Filter
The simplest item on this list and the one most often skipped. A dirty filter restricts airflow, forces the blower motor to work harder, and reduces overall system efficiency the moment heating season starts. If you haven’t changed it since spring, do it this week — not in October when you’re also trying to remember where the extra blankets are.
2. Test the System Before You Need It
Don’t wait for the first cold morning to find out your furnace won’t turn on. Bump the thermostat down a few degrees below room temperature (or use the “heat” test mode if your thermostat has one) and confirm the furnace kicks on, runs, and actually produces warm air at the vents. If nothing happens, you have weeks to get it looked at instead of hours.
3. Clear the Area Around Your Furnace and Vents
Over spring and summer, it’s common for storage boxes, holiday decorations, or general clutter to migrate into the furnace closet or utility room. Combustion appliances need clearance for safety and for proper airflow — clear a few feet around the unit, and make sure supply and return vents throughout the house aren’t blocked by furniture that got rearranged over the summer.
4. Check (or Install) Carbon Monoxide Detectors
Any home with a gas furnace should have working carbon monoxide detectors, ideally on every level and near sleeping areas. Test existing units and replace batteries now, before you’re running the furnace daily. If you don’t have CO detectors, fall is the time to add them — a properly maintained furnace is very low risk, but detectors are cheap insurance against the rare cases where something does go wrong.
5. Look at the Flame (If You Can Safely See It)
On a standard gas furnace, a healthy burner flame is blue with maybe a small tinge of yellow at the tip. A consistently yellow or flickering flame can indicate a combustion problem and is worth having a technician look at rather than diagnosing yourself — this is one of the few items on this list we’d actually recommend leaving to a professional visit rather than checking casually.
6. Schedule a Professional Tune-Up
This is the single highest-value item on the list, and it’s the one that actually prevents mid-winter breakdowns rather than just spotting obvious issues. A professional furnace tune-up typically includes:
- Combustion analysis and burner inspection
- Heat exchanger inspection (a cracked heat exchanger is a genuine safety issue, not a minor repair)
- Ignition system check
- Blower motor and belt inspection
- Electrical connection tightening
- Thermostat calibration check
- Carbon monoxide testing at the unit
Booking this in late August or September means you get a convenient appointment time and, if something needs parts ordered, time to actually get it done before you need the heat daily. Booking it in November means competing with everyone else who waited. See our heating services page for what a full tune-up covers.
7. Check Your Thermostat Batteries and Settings
If your thermostat runs on batteries, replace them now rather than finding out they’re dead during the first cold week. If you have a programmable or smart thermostat, review your schedule — settings from last winter may no longer match your current routine, especially if anyone’s work-from-home schedule has changed.
8. Inspect Ductwork You Can Access
In accessible areas like a basement or crawlspace, take a look at exposed ductwork for obvious gaps, disconnected sections, or crushed ducts. You’re not looking to become an HVAC technician for an afternoon — just checking for anything obviously wrong that a flashlight and five minutes would catch, and flagging anything questionable for your tune-up visit.
9. Bleed Radiators or Check Your Boiler (If Applicable)
If your home uses a boiler and radiators instead of forced air, late summer is the right time for that system’s own version of this checklist — bleeding trapped air from radiators, checking system pressure, and scheduling boiler-specific maintenance. See our dedicated guide on boiler and radiant heat maintenance for the specifics, since boiler prep differs meaningfully from furnace prep.
10. Know Who You’re Calling Before You Need Them
The worst time to start researching HVAC contractors is during a no-heat emergency in a snowstorm. Save a number now — ideally one for a company that’s licensed in your state, has real reviews, and offers real emergency response, not just a voicemail. See our guide on how to choose an HVAC contractor if you’re not already working with someone you trust.
Bonus: What About Your Air Conditioner?
While you’re thinking about the furnace, it’s also the right window to close out your AC properly for the season, especially if you run central air. Clear leaves and debris from around the outdoor condenser before they pile up under fall cover, and if your system has a manufacturer-recommended cover for the compressor, now’s the time to put it on — but skip fully wrapping the unit in plastic, which can trap moisture and encourage rust rather than prevent it. If your AC struggled at all this summer — weak cooling, longer run times, unusual noise — flag it for your technician during the same fall visit rather than waiting until next June to think about it again; a lot of AC issues are easier and cheaper to diagnose and order parts for during the off-season than during the first heat wave of next summer.
The Fall Prep Checklist, All in One Place
- ☐ Replace the air filter
- ☐ Test the furnace before you need it
- ☐ Clear the area around the furnace and vents
- ☐ Test/install carbon monoxide detectors
- ☐ Have a technician check the burner flame and combustion
- ☐ Schedule a professional tune-up
- ☐ Replace thermostat batteries, review the schedule
- ☐ Visually inspect accessible ductwork
- ☐ Address boiler/radiator prep if applicable
- ☐ Save a trusted HVAC contractor’s number now
Why Late Summer Is Genuinely the Best Time to Do This
There’s no marketing spin here — appointment availability really is better in August and September than it is once temperatures drop and everyone’s furnace complaints hit at once. If a tune-up turns up something that needs a part ordered or a bigger repair, you have real lead time to handle it calmly instead of living without heat while you wait. If you’re on the fence about whether your system will make it through another winter or is a candidate for replacement, that conversation is also easier to have now, without the pressure of an active cold snap pushing the decision.
We service furnaces, heat pumps, and boilers across Spokane, Spokane Valley, Liberty Lake, Cheney, and North Idaho including Coeur d’Alene, Post Falls, and Hayden.
Schedule your fall furnace tune-up or call (509) 534-0547 before the calendar fills up.