Quick answer — what to do now
Do a few simple checks yourself (filter, thermostat, visible vents) and book a professional tune‑up before sustained cold arrives. A certified technician will handle safety-critical checks such as combustion, venting and heat‑exchanger inspection. For Ontario homes, also confirm your carbon monoxide (CO) alarms meet current placement rules before winter. (prod-natural-resources.azure.cloud.nrcan-rncan.gc.ca)
Why a pre‑winter check matters
A clean, well‑tuned furnace runs more efficiently, reduces breakdown risk during cold snaps and lowers safety hazards from combustion appliances. Natural Resources Canada recommends scheduling heating system checkups in the fall and notes homeowners can do simple tasks while a qualified technician should perform efficiency tune‑ups and safety inspections. (prod-natural-resources.azure.cloud.nrcan-rncan.gc.ca)
Simple DIY checks you can do this weekend
Do these safe, non‑invasive tasks before calling a technician. If you smell gas or see damage, stop and call for professional help immediately.
- Change or inspect the furnace filter — most disposable filters need checking monthly and replacement at least every 3 months (more often for pets or dusty homes).
- Check the thermostat: replace batteries if it’s not hardwired, verify settings and test heating mode to ensure the system starts and cycles.
- Inspect supply and return vents: make sure vents and registers are open and not blocked by furniture or curtains to maintain airflow.
- Clear around the furnace: keep the area at least 1 metre clear so combustion air and service access are not restricted.
- Look for visible signs: checks for water on the floor near the furnace, loose vent pipes, or disconnected PVC on high‑efficiency furnaces — report these to your service provider.
- Test smoke and carbon monoxide alarms: press the test button and replace batteries as needed. Certified CO alarms are the only way to detect CO. Follow manufacturer instructions for placement and testing. (canada.ca)
What to leave to a technician (and why)
A professional furnace tune‑up includes safety and performance tasks that require tools, training and (in some cases) combustion testing. These items should not be attempted by untrained homeowners.
- Combustion and venting inspection — ensuring flue and intake pipes are sealed, correctly pitched and do not show spillage or backdrafting. Faulty venting can cause combustion gases to enter living spaces. (natural-resources.canada.ca)
- Heat‑exchanger inspection — technicians inspect for cracks or corrosion. A compromised heat exchanger can leak combustion gases including CO.
- Flame sensor/ignitor cleaning and burner inspection — dirty components can cause frequent cycling or no‑heat calls.
- Blower motor, wheel and electrical checks — measure voltages, lubricate if required, and vacuum the blower cabinet to restore airflow.
- Pressure switches, limit switches and safety controls testing — ensures the system shuts down safely if a problem develops.
- Gas‑line and connection leak checks (visual and pressure testing) — any sign of a gas smell requires stopping work and calling a qualified service provider immediately.
- Condensate drain cleaning for high‑efficiency condensing furnaces — prevent blockages that can cause system shutdowns.
Recommended schedule for checks and professional service
Monthly: check or replace disposable filters and test CO/smoke alarms.
Every fall (before heavy use): run DIY checks above and book a professional inspection/tune‑up. NRCan recommends planning a heating system check in the fall. Depending on equipment type and age, a qualified contractor should perform either an annual or at least a biennial inspection — follow your manufacturer’s maintenance schedule and your technician’s advice. (prod-natural-resources.azure.cloud.nrcan-rncan.gc.ca)
Ontario carbon‑monoxide alarm rules you need to know (effective Jan 1, 2026)
Ontario updated CO alarm requirements for existing homes effective January 1, 2026. In many homes a CO alarm must be installed on every storey (floor) and outside sleeping areas where there is a fuel‑burning appliance or an attached garage — owners are responsible for complying. Ensure your alarms are certified to Canadian standards and placed/tested per the manufacturer. If you’re unsure about placement in your home, contact your local fire department or a qualified HVAC professional. (ontario.ca)
When to call Infinite Home Comfort
Book a professional furnace tune‑up or diagnostic if you notice: strange smells (especially gas), yellow or flickering burner flames, frequent cycling, insufficient heat, unusual noises, water near the unit, or a CO alarm activation. Infinite Home Comfort offers fall maintenance and safety inspections across the GTA and services many common models (our verified CRM catalog includes Lennox ML196 and ML296 models). Use our booking link for a pre‑winter tune‑up or emergency repair. (See internal links below.)
What we recommend you include in a professional tune‑up
A complete professional tune‑up typically includes cleaning burners, checking gas pressure, inspecting the heat exchanger and venting, testing safety controls and CO levels, cleaning the blower assembly, replacing filters if requested and verifying thermostat operation. Exact inclusions vary by provider and manufacturer instructions; ask your contractor for a written checklist. (prod-natural-resources.azure.cloud.nrcan-rncan.gc.ca)
Safety first — immediate steps if you suspect a problem
If you smell gas: do not use matches or electrical switches, ventilate if safe, leave the home and call your gas utility and a qualified technician.
If a CO alarm sounds: get everyone outside to fresh air immediately and call emergency services if anyone is unwell. CO is colourless and odourless — only a certified alarm can reliably detect it. (canada.ca)
Conversion links — next steps
Ready to book a pre‑winter tune‑up or request a quote? Use the links below to choose the right service or get an on‑site assessment.
- Soft early CTA — Learn about our furnace services: /furnaces/
- Decision‑point CTA — Request an assessment or quote: /freequote/ (assessment and quote path)
- Closing booking CTA — Book a pre‑winter tune‑up or repair: /booking/ or call: tel:+18337004822
- Related support pages: furnace repair: /furnace-repair/; HVAC repairs and diagnostics: /repair/.
Quick checklist (one‑page summary)
Before winter: change filter, test thermostat, test CO and smoke alarms, clear area, inspect vents, book a professional tune‑up.
Monthly during heating season: check/replace filter, listen for unusual noises, test alarms.
When in doubt: call a qualified technician rather than attempting gas, vent or combustion repairs yourself.
Closing — content ownership and review
This article was prepared for Infinite Home Comfort’s GTA homeowners using verified company context and public authoritative sources. Content should be reviewed annually and after any regulatory change; the company’s booking and service pages linked above provide the next step to schedule maintenance.
Frequently asked questions
How often should I have my furnace professionally serviced?
Schedule a professional inspection in the fall before heavy use. Guidance varies by source and equipment — many manufacturers and contractors recommend annual tune‑ups; Natural Resources Canada advises planning fall checkups and notes some heating equipment may be serviced every one to two years depending on type and age. Follow your manufacturer’s schedule and technician recommendations. (prod-natural-resources.azure.cloud.nrcan-rncan.gc.ca)
Do I need carbon‑monoxide alarms in my home?
Yes. Carbon monoxide alarms are essential — they are the only reliable way to detect CO. Ontario updated alarm placement rules effective Jan 1, 2026 (in many cases requiring CO alarms on every storey and outside sleeping areas where fuel‑burning appliances or attached garages exist). Use certified alarms and test them regularly. (ontario.ca)
Can I clean the burners or inspect the heat exchanger myself?
No. Heat‑exchanger inspection, burner adjustments, combustion and venting checks require trained technicians and proper testing equipment. Attempting these without training can be dangerous and may void warranties. Book a professional tune‑up for these tasks. (natural-resources.canada.ca)
What if my CO alarm goes off?
Immediately move everyone to fresh air (outside) and call emergency services if anyone feels ill. Do not re‑enter the home until it’s declared safe. Contact a qualified HVAC technician to inspect combustion appliances and venting. (canada.ca)