Fall Furnace Maintenance Checklist: Prepare for Ottawa Winter
Ottawa’s heating season runs roughly six months — from late October through April — and your furnace will log thousands of hours during that stretch. A furnace that hasn’t been serviced since last winter is the HVAC equivalent of running a marathon without stretching. It might make it through, but the odds of a breakdown increase significantly, and performance suffers the entire time.
The best time for furnace maintenance is September or October, before temperatures drop and every HVAC company in Ottawa is booked with emergency calls. This checklist walks you through what you can handle yourself and what needs a licensed technician — giving you a clear action plan to prepare your heating system for another Ottawa winter.
At Gas Man Ottawa, we provide comprehensive furnace maintenance that covers every item on this list and more. Call (613) 880-3888 to schedule your fall furnace tune-up before the rush.
Part 1: The Homeowner’s Fall Checklist (DIY Tasks)
These are the tasks you can — and should — handle yourself. They cost nothing, take less than an hour total, and make a meaningful difference in your furnace’s performance and your home’s safety. Do these before your scheduled professional furnace maintenance visit, or as your bare minimum if you can’t get a technician booked right away.
1. Replace Your Furnace Filter
This is the single most important thing you can do for your furnace, and it takes about 30 seconds. A dirty filter restricts airflow, forces the blower motor to work harder, reduces heating efficiency, degrades your indoor air quality, and can cause the heat exchanger to overheat and shut down on a safety limit.
Before the heating season starts, install a fresh filter — ideally a pleated MERV 8–11 filter rather than the cheapest fibreglass panel you can find. Then check it monthly throughout winter and replace it when it looks visibly dirty. With pets, plan on changing it every 4–6 weeks. Without pets, every 2–3 months is typically fine. Write the installation date on the filter frame with a marker so you always know how old it is.
2. Switch Your Thermostat to Heat Mode
It sounds obvious, but every fall Ottawa HVAC companies get calls from homeowners convinced their furnace is broken — only to discover the thermostat was still set to “cool” or “off” from summer. Switch the mode to “heat,” set the fan to “auto,” and set the temperature a few degrees above the current room temperature to trigger a heating cycle. Let the system run for 10–15 minutes and confirm that warm air comes out of all the supply vents.
If you have a battery-powered thermostat, replace the batteries now — don’t wait for the low-battery warning in January. Better yet, if your thermostat is more than 10 years old, consider upgrading to a smart thermostat that programs heating schedules around your routine and can alert you to problems remotely.
3. Open All Registers and Vents
Walk through every room in your home and make sure all supply and return air registers are fully open and unobstructed. Move furniture, rugs, curtains, and storage boxes away from vents. Closing or blocking registers in an attempt to save energy actually increases static pressure in the ductwork, makes the blower motor work harder, and can cause uneven heating throughout the house. While you’re at each register, vacuum the grilles to remove dust buildup from the summer.
4. Inspect the Intake and Exhaust Pipes
If you have a high-efficiency furnace (90%+ AFUE), it has PVC intake and exhaust pipes that exit through your exterior wall — usually one to two feet off the ground. These pipes are critical for safe operation. Before winter, go outside and inspect both pipes. Clear away fallen leaves, grass clippings, garden debris, dirt, insect nests, or anything that could block airflow. In winter, add these pipes to your snow-clearing routine — heavy snowfall can bury them, causing the furnace to shut down or, worse, creating a carbon monoxide hazard.
If you have an older standard-efficiency furnace, it vents through a metal flue pipe into a chimney. Visually inspect the visible portion of the flue for disconnections, rust, holes, or white powdery residue (a sign of condensation and potential draft problems).
5. Test Your Carbon Monoxide Detectors
Every home with a gas furnace, water heater, gas fireplace, or any fuel-burning appliance must have carbon monoxide detectors — Ontario law requires them on every level with a sleeping area. Press the test button on each detector to confirm the alarm sounds. Replace batteries (even if the detector is hardwired — most have battery backup). Replace the entire unit if it’s more than 7 years old. CO detectors have a limited sensor lifespan and become unreliable with age.
6. Clear the Area Around Your Furnace
Your furnace needs clearance for airflow, service access, and safety. Remove any boxes, clothing, paint cans, cleaning products, or flammable materials stored within one metre of the furnace. This applies to the water heater and any other gas appliances in the mechanical room as well. A cluttered furnace room is a fire hazard and makes it harder for a technician to perform thorough maintenance.
7. Check the Condensate Drain
High-efficiency furnaces produce condensation as a byproduct of the combustion process. This water drains through a condensate line — typically a small PVC tube that runs to a floor drain or condensate pump. Check that the drain line isn’t kinked, clogged, or disconnected. If you have a condensate pump, pour some water into it to verify the pump activates and drains properly. A blocked condensate drain will cause your furnace to shut down, and it’s one of the most common fall startup failures.
8. Prepare Your Humidifier
If you have a central humidifier mounted on your furnace, now is the time to get it ready for the heating season. Replace the humidifier pad (also called the water panel or evaporator pad) — these pads calcify and lose effectiveness over a season and should be replaced annually. Turn the humidifier’s water supply valve to the open position (it should have been closed during the cooling season). Set the humidistat to 30–40% relative humidity to start. Clean inside the humidifier housing to remove any mould or mineral buildup.
9. Check for Unusual First-Startup Smells
When you fire up your furnace for the first time in fall, a faint dusty or burning smell is normal — it’s dust that settled on the heat exchanger and burners during the summer burning off. This should dissipate within an hour. However, a strong burning plastic smell, a persistent chemical odour, or a rotten egg smell (indicating a natural gas leak) are not normal. Turn the furnace off immediately and call for service. If you smell gas, leave the house and call your gas utility’s emergency line and Gas Man Ottawa for a gas safety inspection.
Part 2: What a Professional Furnace Tune-Up Covers
The DIY tasks above keep you safe and catch obvious problems. But the core of furnace maintenance — the work that actually extends your furnace’s lifespan, maintains efficiency, and prevents mid-winter breakdowns — requires a licensed technician with the right tools and training. Here’s what a professional furnace tune-up from Gas Man Ottawa includes:
Combustion and Gas System
A technician will inspect the burner assembly and clean burners if needed — dirty burners produce uneven flames that reduce efficiency and can generate excess carbon monoxide. They measure gas pressure at the manifold to confirm it matches the manufacturer’s specifications (too high or too low both cause problems). They test the flame sensor, which detects whether the burner has ignited safely — a dirty flame sensor is the number one cause of “furnace won’t stay lit” calls in Ottawa. They also check the igniter (hot surface or spark) for cracks or wear, since igniters are a common failure point and much cheaper to replace proactively than in an emergency.
Heat Exchanger Inspection
The heat exchanger is the most critical safety component in your furnace. It separates the combustion gases (including carbon monoxide) from the air circulating through your home. A cracked heat exchanger allows CO to mix with your breathable air — a potentially life-threatening situation. During a furnace inspection, the technician visually inspects the heat exchanger for cracks, corrosion, or deterioration. On older furnaces, this is especially important — heat exchangers typically last 15–20 years, and failure risk increases significantly beyond that point. A cracked heat exchanger results in a “red tag,” meaning the furnace must be shut down until repaired or replaced.
Electrical Components
The technician checks all electrical connections — loose or corroded wiring causes intermittent operation and can be a fire hazard. They test the blower motor’s amperage draw against specifications to detect early signs of motor bearing wear (a motor drawing too many amps is working too hard and will eventually fail). They verify the control board is operating correctly and test safety limit switches and rollout switches that protect against overheating.
Airflow and Distribution
The technician measures temperature rise — the difference between return air temperature and supply air temperature — to confirm it falls within the manufacturer’s specifications. Temperature rise that’s too high indicates restricted airflow (dirty filter, closed registers, undersized ductwork). Temperature rise that’s too low can indicate a gas pressure issue, dirty burners, or an oversized blower speed setting. They also check static pressure across the system — high static pressure means the blower is fighting against restrictions that reduce efficiency and strain components.
Flue and Venting
The technician inspects the entire venting system — from the furnace to the exterior termination — for proper slope, secure connections, corrosion, and blockages. For high-efficiency furnaces, they verify the intake and exhaust pipes are properly installed and clear. For standard-efficiency furnaces with chimney venting, they check for proper draft to ensure combustion gases exit the home safely. Improper venting is a primary source of carbon monoxide problems.
Safety Testing
A complete furnace tune-up includes testing for carbon monoxide in the flue gases and at the supply registers. The technician also tests gas line connections with a combustible gas leak detector to confirm there are no leaks at the furnace, gas piping, or connections. These safety tests can’t be replicated with DIY methods — they require calibrated instruments and professional training.
Fall Furnace Maintenance Checklist Summary
| Task | DIY or Pro? | When |
|---|---|---|
| Replace furnace filter | DIY | September + monthly all winter |
| Switch thermostat to heat, test run | DIY | Early October |
| Open all registers and vents | DIY | Before first use |
| Inspect intake/exhaust pipes | DIY | October + after every major snowfall |
| Test CO detectors, replace batteries | DIY | October (and monthly test) |
| Clear area around furnace | DIY | Before heating season |
| Check condensate drain and pump | DIY | Before first use |
| Replace humidifier pad, open water supply | DIY | Before heating season |
| Burner cleaning and gas pressure test | Professional | Annually (Sept–Oct ideal) |
| Heat exchanger inspection | Professional | Annually |
| Flame sensor and igniter check | Professional | Annually |
| Electrical connections and amp draws | Professional | Annually |
| Temperature rise and static pressure | Professional | Annually |
| Flue and venting inspection | Professional | Annually |
| CO and gas leak testing | Professional | Annually |
Why Annual Furnace Maintenance Matters in Ottawa
Some homeowners skip annual furnace maintenance because the furnace seems to work fine. It’s working — so why spend $150–$250 on a tune-up? Here’s the reality:
Prevent Mid-Winter Breakdowns
The majority of furnace repair calls in Ottawa happen between December and February — when demand is highest, wait times are longest, and the consequences of no heat are most serious. Most of these breakdowns involve components that a fall furnace inspection would have caught: a weak flame sensor, a cracking igniter, a failing capacitor, or a condensate drain that’s slowly clogging. A $150 maintenance visit in October prevents a $300–$500 emergency repair in January — plus the stress and discomfort of a cold house.
Maintain Energy Efficiency
A furnace that hasn’t been serviced loses efficiency gradually. Dirty burners produce less heat per cubic metre of gas. A dirty blower wheel moves less air, forcing the system to run longer. Gas pressure that’s drifted out of specification wastes fuel. These inefficiencies add 5–15% to your heating bill — and in Ottawa, where heating costs already run $1,500–$3,000+ per season, that’s $75–$450 in wasted money. The tune-up pays for itself in fuel savings alone.
Extend Furnace Lifespan
A well-maintained furnace in Ottawa typically lasts 18–25 years. A neglected furnace may only last 12–15 years before requiring replacement. Given that a new furnace installation costs $4,000–$8,000+, the math on annual maintenance is straightforward: spending $150–$250 per year to add 5–10 years of life to a furnace saves you thousands in premature replacement costs.
Protect Your Warranty
Most furnace manufacturers require annual furnace maintenance by a licensed technician to maintain warranty coverage. If a major component like the heat exchanger fails and you can’t provide maintenance records, the manufacturer can deny the warranty claim — leaving you responsible for a repair that could cost $1,500–$2,500+ or a full replacement. Keep your maintenance records. They’re worth thousands of dollars in warranty protection.
Keep Your Family Safe
Carbon monoxide from a cracked heat exchanger or faulty venting kills Canadians every year. A gas leak from deteriorated fittings creates an explosion risk. These are not theoretical concerns — they’re the specific hazards that professional furnace maintenance is designed to detect. The safety inspection alone — checking the heat exchanger, testing for CO, verifying proper venting, and scanning for gas leaks — is worth the cost of the entire tune-up.
What Furnace Maintenance Costs in Ottawa
A standard furnace tune-up in Ottawa typically costs $150–$250, depending on the scope of the inspection and the company. Here’s what influences the price:
| Service Level | Typical Cost | What’s Included |
|---|---|---|
| Basic tune-up | $100 – $150 | Filter check, burner inspection, basic safety test, visual inspection |
| Comprehensive maintenance | $150 – $250 | Full cleaning, combustion analysis, CO testing, gas leak scan, all electrical checks, temperature rise measurement |
| Maintenance plan (annual) | $15 – $25/month | Annual tune-up + priority scheduling, discount on repairs, extended coverage |
Gas Man Ottawa provides comprehensive furnace maintenance that covers every inspection point listed in this article. Call (613) 880-3888 to book your fall appointment.
Additional Fall Tasks for Your Complete HVAC System
While you’re focused on the furnace, these related tasks round out your fall home preparation:
Schedule Air Conditioner Shutdown
Turn off the breaker to your air conditioner‘s outdoor unit to prevent accidental operation during cold weather. Remove any debris from around the condenser. Some homeowners cover the top of the unit with plywood (secured with a weight) to prevent ice and debris from falling in — but don’t wrap the entire unit, as this traps moisture and promotes corrosion.
Check Your HRV/ERV
If you have a Heat Recovery Ventilator (HRV), clean or replace the filters, wash the heat exchange core if your model allows it, and verify the drain line is clear. Your HRV works hardest during winter, providing fresh air while recovering heat — it needs to be clean and functional before the heating season starts.
Service Your Gas Fireplace
If you have a gas fireplace, schedule gas fireplace maintenance before winter as well. Pilot light assemblies, thermocouples, and gas valves need annual inspection. A fireplace that hasn’t been serviced may not light when you need it — and a malfunctioning gas fireplace poses the same CO and gas leak risks as a furnace.
Inspect Ductwork
Walk through your basement or mechanical room and visually inspect exposed ductwork for disconnections, loose joints, visible gaps, or signs of deterioration. Leaky ducts waste 20–30% of your heated air — you’re literally heating your crawlspace or wall cavities instead of your living space. If you notice issues, have them sealed during your maintenance visit.
Bleed Your Radiators (If Applicable)
If your home uses a boiler and radiator system instead of a forced-air furnace, bleed each radiator to release trapped air that prevents proper heat distribution. You’ll need a radiator key and a cloth — open the bleed valve until water flows steadily, then close it. Schedule boiler maintenance before the heating season as well.
When to Call a Professional Immediately
Some furnace issues can’t wait for a scheduled maintenance visit. Call for service right away if you notice a yellow or flickering burner flame (should be steady blue) — this indicates incomplete combustion and potential CO production. A rotten egg or sulphur smell near the furnace or gas lines means a possible gas leak — leave the house and call your gas utility emergency line. A CO detector alarm is always an emergency — evacuate and call 911. Unusual banging, screeching, or grinding noises indicate mechanical failure that can worsen if the system continues to run. The furnace starts and stops repeatedly (short cycling), which indicates a safety switch is triggering — the system is detecting an unsafe condition.
Don’t ignore these warning signs. A furnace problem that gets addressed promptly is almost always cheaper and safer than one that’s left to escalate.
Frequently Asked Questions: Fall Furnace Maintenance
How often should I get a furnace tune-up?
Once per year, ideally in September or October before the heating season begins. Annual furnace maintenance catches developing problems, maintains efficiency, protects your warranty, and ensures safe operation throughout Ottawa’s long winter. Gas Man Ottawa’s furnace maintenance service covers all safety and performance checks. Call (613) 880-3888 to book your appointment.
How much does furnace maintenance cost in Ottawa?
A comprehensive furnace tune-up in Ottawa typically costs $150–$250, depending on the scope of the inspection. Basic tune-ups start around $100–$150. This investment prevents breakdowns that cost $300–$1,000+ in emergency repairs, maintains 5–15% energy efficiency, and protects your manufacturer warranty. The tune-up pays for itself within the first heating season.
Can I do furnace maintenance myself?
You can handle filter replacement, thermostat checks, visual inspections, vent clearing, and CO detector testing yourself — and you should. But combustion testing, gas pressure measurement, heat exchanger inspection, electrical testing, and CO analysis require a licensed technician with calibrated instruments. The DIY tasks are important, but they don’t replace professional furnace maintenance.
What happens if I skip furnace maintenance?
Skipping annual furnace maintenance increases the risk of mid-winter breakdowns, gradually reduces heating efficiency (adding 5–15% to your gas bill), shortens the furnace’s lifespan by years, voids most manufacturer warranties, and leaves potential carbon monoxide hazards undetected. One skipped year probably won’t cause immediate problems, but the risks compound — most furnace emergencies happen in systems that haven’t been maintained for 2+ years.
When should I replace my furnace instead of maintaining it?
Consider furnace replacement if the unit is 20+ years old, the heat exchanger is cracked, repairs are becoming frequent (2+ per season), or your heating bills keep climbing despite maintenance. A new high-efficiency furnace (95–98% AFUE) can cut heating costs by 25–35% compared to an older 80% AFUE unit. Visit our repair or replace guide for more details.
Why does my furnace smell when I first turn it on in fall?
A faint dusty or burning smell during the first startup is normal — it’s dust that accumulated on the heat exchanger and burners during the summer burning off. It should dissipate within an hour. If the smell is strong, persists for more than a few hours, smells like burning plastic or rubber, or smells like rotten eggs (gas), turn the furnace off and call for service immediately.
How often should I change my furnace filter?
Check it monthly during the heating season and replace it when it looks dirty. Most households need a new filter every 1–3 months depending on filter type, whether you have pets, and how many occupants are in the home. A clean filter improves both heating efficiency and indoor air quality. Use a pleated MERV 8–11 filter for the best balance of filtration and airflow.
Is a furnace maintenance plan worth it?
For most Ottawa homeowners, yes. A maintenance plan ($15–$25/month) typically includes an annual tune-up, priority scheduling during peak season (when non-plan customers wait days for service), discounts on repairs, and extended coverage on certain components. If your furnace is more than 5 years old, the priority scheduling benefit alone is worth the cost — nobody wants to wait three days for heat in January.
Book Your Fall Furnace Tune-Up With Gas Man Ottawa
Don’t wait for the first cold night to find out your furnace isn’t ready. Gas Man Ottawa provides thorough furnace maintenance across Central Ottawa, Kanata, Orleans, Barrhaven, Nepean, Manotick, and Gloucester.
Call (613) 880-3888 or contact us online to schedule your appointment. Check our customer reviews and our service guarantee.
Need help with other HVAC systems? See our services for AC maintenance, heat pump maintenance, boiler maintenance, and gas fireplace maintenance.