A carbon monoxide alarm or a gas smell comes before everything else
If the carbon monoxide alarm sounds, or people in the house feel headachy, sick or drowsy and it eases when they step outside, get everyone out and call 911 from outside. Do not stay in to look for the source. If you smell gas, leave without switching lights or appliances on or off, and call your gas utility's emergency line once you are outside.
A cracked heat exchanger is the one furnace fault to be direct about. It can let combustion gases, including carbon monoxide, into the air the blower moves through the house. If one is found, the furnace should not be run until it is dealt with. The Ontario Fire Code requires a working carbon monoxide alarm next to each sleeping area in a home with a fuel-burning appliance. Our guide on carbon monoxide and gas furnaces covers placement and testing.
No heat on a cold night usually has a short list of causes
Some checks are safe for anyone. Make sure the thermostat is set to heat and a few degrees above room temperature, and replace its batteries if it has them. Find the furnace switch, which looks like a light switch on the wall or ceiling near the unit, and make sure it is on. Check the breaker. Look at the filter, and make sure the front panel is seated properly, because many furnaces will not start with the door switch open.
Leave the rest to a technician. Do not open the burner area, bypass a switch or keep resetting a furnace that has locked itself out. When the simple checks do not bring the heat back, the cause is usually a worn igniter, a dirty flame sensor, a pressure switch that is not closing or a control board fault. Each one is a normal repair, and none needs guesswork to find.
Cold air from the vents points to a few familiar faults
First, look at the thermostat fan setting. On ON, the blower runs between heating cycles and the air feels cool. On AUTO, it runs only while the burners are lit.
If the setting is right and the air is still cold, the furnace is usually lighting and then shutting the burners off. A clogged filter can make it overheat and trip its high limit. A coated flame sensor can make it shut the gas off seconds after lighting. On a high-efficiency furnace, a blocked drain or vent can stop the burners while the fan keeps going. Our guide on why a furnace blows cold air walks through these in order.
Short cycling and new noises are worth a look before they get worse
Short cycling means the furnace starts, runs briefly and stops, over and over. It wears parts and leaves rooms uneven. The usual causes are a dirty filter, a flame sensor, a thermostat in a poor spot, or a furnace that is too large for the house. That last one is common in tight modern houses, where a big unit reaches temperature quickly and shuts off.
Noises each have a likely source. A squeal often comes from a blower motor bearing. A rattle or hum from the side of the cabinet is often the inducer motor. Gurgling on a high-efficiency furnace usually points to the condensate drain. A bang or loud whoosh when the burners light can mean delayed ignition, and that one should be looked at soon rather than lived with. Turn the thermostat down and arrange a visit.
Binbrook's newer and older houses tend to fail in different ways
In the newer subdivisions around Fall Fair Way, Fletcher Road, Royal Winter Blvd, Binhaven Blvd and Reid Ave N, most houses have high-efficiency condensing furnaces vented through the side wall with plastic pipe. The common calls are blocked condensate drains and vents buried by snow. After a storm, it is safe to clear snow from around the pipes by hand, then switch the furnace off and on. If it still will not light, or the pipes keep blocking, the venting may need attention.
In the older village core along Highway 56 and Binbrook Road, many houses were heated with oil or coal before being converted to gas. Technicians may find chimneys that were never relined and ducts that are on the small side. Mid-century houses on Binbrook Road often have mid-efficiency furnaces vented through the chimney, and many are near the end of their life, with worn heat exchangers and venting that does not suit the furnace. When a repair is large on an old unit, our guide on how long a furnace lasts and the replacement page can help you weigh the choice.
A repair visit follows a clear order, with the price in writing first
You describe what the furnace is doing and when it started. The technician confirms the symptom with you, tests the system and explains the fault in plain words. You then get a written price, and nothing is fitted until you approve it. If the furnace is old and the fault is a major one, you can ask for the repair and replacement options side by side before deciding.
In Ontario, gas furnaces must be serviced by a contractor registered under Ontario Regulation 212/01 and worked on to the CSA B149.1 installation code. Work is performed by TSSA-certified gas technicians. Many of the faults above, especially drains, filters and flame sensors, are the kind a seasonal maintenance visit can catch early. To start, use the quote page.