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An HVAC contractor designs, installs, services and repairs these parts so they work together. That matters because a problem in one part often shows up somewhere else. A clogged filter can make a furnace overheat, leaky ducts can leave upstairs bedrooms cold, and a tightly sealed renovation without enough ventilation can lead to condensation on windows and stale air.
Homeowners usually call an HVAC company when a system stops working, when equipment is getting old, when they renovate or finish a basement, or when they are thinking about switching energy source, for example from oil or electric baseboards to a heat pump. Because much of this work involves gas, refrigerant and electrical wiring, it is regulated in every province and belongs with licensed technicians.
Types of home heating, cooling and ventilation systems in Canada
- A forced-air furnace, fuelled by natural gas, propane, oil or electricity, heats air and sends it through the house in ducts.
- A hot-water boiler feeds radiators, baseboard convectors or in-floor heating loops.
- Electric baseboards, found in many Quebec homes, heat room by room, each with its own thermostat.
- A central heat pump uses the existing ductwork to heat in winter and cool in summer.
- A ductless mini-split heat pump uses wall-mounted indoor units and suits homes without ducts, additions and basements.
- A ground-source, or geothermal, heat pump draws heat from the earth through a loop buried on the property.
- A central air conditioner only cools and usually shares the furnace's blower and ducts.
- A heat recovery ventilator (HRV) or energy recovery ventilator (ERV), usually called an air exchanger, replaces stale indoor air with fresh outdoor air while recovering some of the heat.
What happens during an HVAC system assessment
A useful assessment starts with the house rather than the equipment. The technician looks at the size and layout of the home, its insulation and windows, where the ducts run, how each floor is heated and cooled, and which rooms are always too hot or too cold. They then check the age and condition of the furnace or boiler, the outdoor unit, the thermostat, the venting and the air exchanger.
From there they can tell you whether the system only needs a repair or a tune-up, whether one part such as the ductwork or the ventilation is holding the rest back, or whether it is time to plan a replacement. If you are weighing a different kind of system, ask how it would fit with what you already have, including the electrical panel, the venting and the space available for new equipment.
Signs your HVAC system needs attention
- Some rooms stay noticeably colder or warmer than others, whatever the thermostat setting.
- The system runs almost nonstop, or starts and stops every few minutes.
- Your heating or electricity bills climb although your habits have not changed.
- You hear new banging, squealing, rattling or humming from the furnace, the ducts or the outdoor unit.
- Windows fog up or drip on the inside in winter, or the house feels damp and stuffy.
- There is more dust than usual, or a musty smell when the system starts.
- Water is pooling around the furnace, the air conditioner or the heat pump's indoor unit.
HVAC maintenance that keeps a home comfortable and safe
Regular maintenance keeps a system safe and efficient and catches small problems before the coldest night of the year. Health Canada recommends having fuel-burning appliances such as furnaces inspected by a professional at least once a year, or as the manufacturer instructs.
- Check the furnace or air handler filter often, and replace or clean it as the manufacturer recommends.
- Keep supply registers and return grilles clear of furniture, rugs and storage boxes.
- Clean the air exchanger's filters and core following its manual.
- Keep plants, leaves and snow away from outdoor units and from exhaust and intake vents.
- Book a professional tune-up of the heating before winter and of the cooling before summer.
Getting your heating and cooling ready for each season
In the fall, before you need heat every day, give the heating a test run while technicians are still easy to book. Check that every room warms up, that the thermostat responds and that your carbon monoxide alarms work, and make sure nothing is stored against the furnace or the water heater.
Through the winter, look at the exterior exhaust and intake vents during and after heavy snow or freezing rain, as Health Canada advises, since a buried vent can shut a high-efficiency furnace down or push exhaust back indoors. In spring, clear debris from around the outdoor air conditioner or heat pump and have the cooling checked before the first heat wave, when service calls pile up.
Heating and cooling emergencies: when to stop and call for help
- If you smell gas, don't touch switches or appliances; get everyone outside and call your gas distributor's emergency line or emergency services from there.
- If a carbon monoxide alarm sounds, leave for fresh air right away without looking for the source, then call 9-1-1 or your fire department from outside.
- A furnace that quits during a cold snap is urgent: open cabinet doors under sinks on outside walls and use only certified electric heaters while you wait.
- Water or ice building up around a furnace, boiler or heat pump can mean a blocked condensate drain or a leak, so switch the equipment off and call a technician.
- A burning smell that lingers, sparks, or a breaker that trips again after a reset calls for a licensed technician rather than another reset.
HVAC Contractors: frequently asked questions
What does an HVAC contractor do?
An HVAC contractor installs, maintains and repairs the equipment that heats, cools and ventilates your home: furnaces, boilers, heat pumps, air conditioners, ductwork, thermostats and air exchangers. Many also handle gas lines and indoor air quality equipment such as humidifiers and filters.
What is the best heating system for a Canadian winter?
There isn't one answer for every home. The right choice depends on which energy sources are available where you live, whether the house has ducts, how well it is insulated and how cold your region gets. A heat pump paired with a furnace or electric backup, a high-efficiency furnace, or a boiler with radiant heat can each be a good fit.
Do I need an air exchanger in my house?
Newer and well-sealed homes usually need mechanical ventilation, because they no longer leak enough outdoor air to replace stale, humid indoor air. Condensation on windows, lingering cooking smells and a stuffy feeling are common hints. An HVAC contractor can tell you whether an HRV or ERV suits your house.
How often should an HVAC system be serviced?
Health Canada recommends a professional inspection of fuel-burning appliances such as furnaces at least once a year, or as the manufacturer instructs. Cooling equipment and heat pumps also benefit from a yearly check, ideally before the season when you rely on them most.
Can I switch from oil or electric baseboards to a heat pump?
Often, yes. A home with ducts can usually take a central heat pump, while a home heated by baseboards can use ductless wall units in the main living areas. The contractor also needs to confirm that your electrical panel can support the new equipment and to plan what happens to the old system.
Can one company handle my heating, cooling and ventilation?
Many HVAC companies do all three, which makes it easier to get parts that work well together. Gas work, refrigeration and electrical connections each require their own qualifications, so check that the company holds the licences your province requires for the specific job.
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Written by the LokalMatch editorial team. Reviewed by Zubair Afzal on September 10, 2026. How we write and check our guides