Heating season has a way of arriving faster than expected. One day, it’s a perfectly comfortable October afternoon, and the next, you are turning up the thermostat for the first time in months. It can be tempting to simply switch the heat on and wait for the home to warm up – but after months of sitting idle, your heating system needs a quick once-over before it goes back into regular service.

Start with the furnace. Before turning it on, take a look around. Furnaces need adequate clearance for proper airflow – make sure the area is clear of boxes, paint cans, laundry, and any other household storage.

• If your furnace has a pilot light – check the flame. A healthy pilot light should be a small, steady blue flame. If the flame is yellow, weak, or dancing wildly, it indicates a problem. If you see no flame, the pilot light is out and the furnace won’t work – unless it’s equipped with an auto-pilot which ignites on demand.
• If your furnace has a diagnostic LED light – a slow, steady blink typically means normal standby mode, while rapid or repeating flashes may point to a specific issue. Check the sticker printed on the inside of your furnace service panel to translate what the specific blink count means.
• If your furnace has visible venting pipes – check that they appear securely connected and undamaged. Anything that looks loose, corroded, cracked, or disconnected needs to be checked by a qualified HVAC technician.

Replace the filter. As dust builds up, it leads to restricted airflow, and the blower then has to work harder to move air through the system. The replacement filter needs to be the correct size and installed in the direction indicated by the arrow on the frame. Follow the furnace manufacturer’s recommendations for the appropriate MERV rating.

Test the thermostat. Set it to a few degrees above the current room temperature and wait for the system to respond. It’s normal for some furnaces to delay starting the blower while the heat exchanger warms up.

How’s the airflow? Take a walk through the home, making sure that the supply vents and return-air grilles aren’t blocked by furniture, rugs, curtains, or other household items. Supply vents deliver heated air into each room, while return grilles allow cooler air to travel back to the furnace to be reheated. Both sides of that cycle matter – if air cannot move freely back to the system, the furnace cannot circulate it as effectively.

Pay attention to what you hear and smell. A brief dusty smell during the first heating cycle is common, but persistent odours, rattling, banging, grinding, or repeated clicking should be checked by a professional. If something doesn’t sound or smell right, it’s better to deal with it now rather than waiting for temperatures to nosedive.