Some signs mean the system needs attention now
Water pooling under a high-efficiency furnace, a gurgle from the drain line, or a furnace that lights, runs briefly and shuts off usually points to a blocked condensate drain or trap. A dirty flame sensor gives a similar pattern. Both are routine maintenance items, and both can leave you without heat if they are skipped.
Soot near the draft hood, a yellow or lazy flame, an exhaust smell in the basement or a carbon monoxide alarm going off are different. If the alarm sounds, get everyone outside and call the fire department or your gas utility first. A tune-up is not the answer to those signs; a repair visit is. See furnace repair.
In summer, ice on the copper line at the outdoor unit, a breaker that keeps tripping or water around the indoor coil means the air conditioner needs a look before the next hot spell. See air conditioner repair.
New sealed homes in Avalon neglect the drains and ventilator filters
Houses in Avalon and the other newer streets usually have a high-efficiency condensing furnace with two plastic pipes out the side wall, and a tightly sealed shell with a mechanical ventilator. The furnace makes water as it runs. That water goes through a trap and a drain line that can clog with sludge, or freeze where it runs near an outside wall.
A tune-up cleans and flushes the trap and line, checks the slope, and confirms the pressure switch hoses are clear. The intake and exhaust terminals outside are checked for nests, damage and clearance from snow. The ventilator filters and core are cleaned or replaced. In a sealed house they are often the most neglected part of the system, and the reason the air feels stale by late winter.
Between visits, clear the side-wall vents after each snowfall. A drift over them will shut the furnace off.
Chimney-vented furnaces north of the river need the venting checked
Many 1960s houses around Shetland Street were built with a standard-efficiency gas furnace vented into the chimney. Some still have one. Others have a newer furnace with the water heater left on its own in the old flue. Maintenance on these homes includes a draft check, a look at the vent connector for rust and gaps, and a spillage test at the draft hood.
An oversized chimney serving only a water heater can stay cold, which leads to condensation and poor draft. If that is what the technician finds, you are told and given a written price for a liner. Nothing is fitted until you approve it. If the furnace itself is near the end and you are weighing options, see furnace installation and replacement.
Older homes around Edinburgh Square have their own checklist
Houses near Edinburgh Square and Caithness Street have often been converted more than once: a boiler with radiators, a gravity system, or forced air added later through tight, retrofitted ducts. Maintenance here means checking the boiler's burner, controls and relief valve, bleeding radiators, and looking at how air moves through ductwork that was never designed for it.
Old pipe and duct insulation in these houses can contain asbestos. If it looks damaged or crumbly, it is left undisturbed and pointed out to you so it can be dealt with properly.
Spring service readies the central air before it is needed
An air conditioner tune-up covers the outdoor coil, the condensate drain at the indoor coil, electrical connections, the capacitor and contactor, and refrigerant operating pressures. Grass clippings and seed fluff pack the outdoor coil and cut its capacity. Work is performed by 313A refrigeration and air conditioning mechanics. In Ontario, refrigeration and air conditioning is a compulsory trade.
Houses from the 1960s often have ducts sized for heat, not cooling, which shows up as warm upstairs rooms. A tune-up will not change duct size, but it will tell you whether the problem is the equipment or the ducts. For homes with small or retrofitted ducts, see air conditioning installation. A heat pump heats and cools, so it benefits from service before both seasons.
A maintenance visit follows a set order
The technician asks what the system has been doing, then shuts it down and works through it: filter, burner and flame, igniter and flame sensor, heat exchanger inspection, blower, safety controls, venting, gas pressure and combustion readings. Work is performed by TSSA-certified gas technicians. Natural gas and propane appliances are serviced to the CSA B149.1 installation code.
Many furnace and air conditioner manufacturers make regular professional maintenance a condition of their warranty. Keep the service record with your manual; it is what you show if a part fails while still covered. A clean, correctly adjusted system also burns less gas and draws less power than a neglected one.
Ask about your carbon monoxide alarms during the visit. The Ontario Fire Code requires a working alarm next to each sleeping area in a home with a fuel-burning appliance, a fireplace or an attached garage. If anything needs repair, you get a written price first. Book heating service in early fall and cooling service in spring through the quote page.