Furnaces FAQ

What is a variable speed furnace?

A variable speed furnace is a type of heating system that can adjust how fast its blower motor runs, instead of operating at just one fixed speed like traditional furnaces.

In a standard furnace, the blower is either fully on or off. A variable speed furnace, however, can run at many different speeds depending on your home’s heating needs. This allows it to deliver more consistent airflow and maintain a more even temperature throughout the house.

Because it doesn’t constantly start and stop at full power, a variable speed furnace is typically:

More energy-efficient, using only the power needed at a given time
Quieter, since it often runs at lower speeds
Better at maintaining comfort, with fewer temperature swings
Improved for air quality, as it can circulate air more consistently through filters

Overall, a variable speed furnace offers greater comfort and efficiency compared to single-stage or multi-stage furnaces.

The quietest furnaces today are variable-speed (modulating) furnaces.

Instead of turning on at full power all at once, these furnaces start slowly and adjust their speed based on how much heat your home needs. This means:

Less sudden noise when they start
Smoother, quieter operation
More even temperature in your home

Look for features like:

Variable-speed blower motors
Two-stage or modulating burners
Good insulation inside the furnace cabinet

Also, proper installation matters a lot. Even a quiet furnace can be noisy if it’s not installed correctly or if the ductwork isn’t designed well.

Using natural gas instead of electricity can be important mainly because of how the energy is produced and used.

In Ontario, a lot of electricity is generated in ways that can be more expensive during high demand times. When many people use electricity for heating (especially in winter), it puts extra pressure on the electrical system. This can lead to higher costs and a greater need for backup power sources.

Natural gas, on the other hand, is often more efficient and cost-effective for heating homes. Gas heating systems can produce heat quickly and usually cost less to run compared to electric heating.

Also, using natural gas for things like heating helps reduce the overall demand on the electrical grid. This keeps the system more stable and helps avoid spikes in energy prices during peak times.

Yes, your new furnace will likely operate a bit differently, but in a good way.

Modern furnaces are designed to be more energy-efficient and consistent. Instead of turning on and off in big bursts like older units, many newer systems run in longer, quieter cycles to maintain a steady temperature. You may notice fewer temperature swings, improved comfort, and lower energy bills.

Some models also use variable-speed blowers or smart thermostats, which help distribute heat more evenly throughout your home.

Not always. Many modern high-efficiency furnaces don’t use a traditional chimney, they vent through plastic pipes instead. If your new furnace is mid- or high-efficiency, your existing chimney may be oversized or unsuitable, which can lead to poor draft and moisture damage. In some cases, a chimney liner or a different venting system is required. It’s best to have a licensed HVAC professional assess your setup before reusing the chimney.

Most carbon monoxide (CO) detectors don’t last forever, typically they need to be replaced every 5 to 7 years, depending on the manufacturer.

You can tell it’s time to replace yours if:
The unit is beeping or chirping regularly (even after changing batteries)
It shows an “end of life” warning on the display
The manufacture date on the back is over 5–7 years old
The test button fails or the unit doesn’t respond properly

For safety, always follow the manufacturer’s guidelines and replace the detector immediately if it signals end-of-life.

If you’re going away for a few days, set your thermostat to around 16°C (60°F) in winter. This helps save energy while keeping your home warm enough to prevent frozen pipes and excess moisture.

In summer, set it to around 28°C (82°F) to reduce cooling costs while protecting your home from excess heat and humidity.

The proper furnace size depends on your home’s square footage, insulation, ceiling height, window quality, and Ontario’s climate. An oversized or undersized furnace can lead to higher energy bills and reduced comfort. The best way to determine the right size is through a professional heat loss calculation performed by a licensed HVAC technician.

Yes. Every home with gas appliances should have a carbon monoxide (CO) detector installed, especially near sleeping areas. It helps alert you to dangerous CO leaks and improves household safety.

Your gas furnace should be professionally serviced once a year, ideally before winter. Regular maintenance improves efficiency, safety, and system lifespan.

If your furnace is over 15 years old, needs frequent repairs, or struggles to heat your home, replacing it before it fails can save you from emergency breakdowns and higher energy bills during winter.

Spring and fall are usually the best times because HVAC companies are less busy, which can mean better scheduling and promotional pricing.

Schedule annual maintenance, replace filters regularly, keep vents clear, and install carbon monoxide detectors. Professional inspections help identify safety concerns early.

Furnace filters vary by thickness and MERV rating. Higher-rated filters capture smaller particles like dust, pollen, and pet dander, but some systems require specific filter types for proper airflow.

Yes, yearly cleaning and inspection are recommended. Dust buildup can reduce efficiency and may affect indoor air quality and system performance.

“Auto” runs the fan only during heating or cooling cycles and is more energy efficient. “On” keeps the fan running continuously, which can improve air circulation and filtration.

Uneven temperatures can often be improved by adjusting dampers, sealing duct leaks, improving insulation, or upgrading to a zoned HVAC system. A professional assessment can help identify the cause.

Two-stage heating means your furnace can operate at two levels: a lower setting for mild weather and a higher setting for colder days. This improves comfort, efficiency, and temperature consistency.

A heat pump is an energy-efficient system that both heats and cools your home by transferring heat instead of generating it. It works well in Ontario when paired with a furnace or as part of a hybrid heating system.