How do you know a furnace is due for replacement?
Most furnaces give some warning. Repeat repairs over a couple of winters, rooms that never quite warm up, a blower that runs longer than it used to, rising gas use with no change in how you live, and rust or water around the base are the usual signs. None of these on its own means the furnace has to go, but together they are worth a conversation.
On the Stoney Creek mountain, the Felker, East Felker and Heritage Green subdivisions were built from the 1990s onward, and many of their original forced-air gas furnaces are now near the end of their life. Technicians often find worn inducer motors, failing control boards and wear on the heat exchanger in these units. When one of those parts fails on an older furnace, it is reasonable to price both the fix and a new furnace before deciding.
The fault that settles the question is a cracked heat exchanger. It can let combustion gases, including carbon monoxide, into the air the furnace moves through the house, so a furnace with a confirmed crack should not be run. Whatever furnace you have, the Ontario Fire Code requires a working carbon monoxide alarm next to each sleeping area of a home with a fuel-burning appliance, and now is a good time to test yours.
What can you safely check before deciding the furnace is finished?
A furnace that has stopped is not always a furnace that has died. It is safe to check that the thermostat is set to heat and has fresh batteries, that the switch beside the furnace (it looks like a light switch) is on, that the breaker has not tripped and that the filter is not clogged. On a high-efficiency furnace, look outside for the two plastic pipes in the wall and clear any snow or ice from around them by hand.
Leave the rest alone. Do not remove burner covers, bypass switches or try to light anything, and if you smell gas, leave the house and call the gas utility from outside. If the simple checks do not bring the heat back, our guide to a furnace that won't turn on explains what a reset does and when to stop, and a repair visit will show whether the furnace has more winters left in it.
How is a new furnace sized for your house?
A furnace that is too large heats in short bursts, wears faster and leaves the house uneven; one that is too small runs constantly on the coldest nights. The right size comes from the house itself: its floor area, insulation, windows and air leakage, and from what the ductwork can actually carry. The old furnace's rating is only a clue, since many were oversized from the start.
The ducts matter as much as the furnace. In the older houses of Olde Towne, along King Street and Lake Avenue, heating was added long after the houses were built, and technicians often find odd or undersized ducts. A modern variable-speed blower pushed through narrow returns can be noisy and work harder than it should. Where the ducts will limit a new furnace, you are told before the price is written, along with what a return-air change would involve.
If you are weighing gas against electric heat, a cold-climate or hybrid heat pump can share the ductwork with a smaller furnace. It is one option among several, and it is explained without pressure.
What happens to the chimney and venting when the furnace changes?
A high-efficiency condensing furnace vents through plastic pipe, usually out the side wall, instead of up the chimney. In an older house that can leave the chimney serving only a gas water heater, or nothing at all. An unlined masonry chimney left with one small appliance may not draft properly, so the venting is checked as part of the replacement and you are told if a liner or a different vent is needed.
New vent terminals are placed where drifting snow is less likely to bury them, and the condensate drain is run to a floor drain or pump so it does not freeze or back up. Gas and propane appliances in Ontario are installed to the CSA B149.1 Natural Gas and Propane Installation Code, adopted under Ontario Regulation 212/01, and that code sets out where vents may go and how the gas line is connected.
In some Olde Towne houses, technicians also come across old oil tanks left behind after a fuel conversion. If one turns up, you will hear about it, since it is something to plan for separately.
How does an installation go, from first visit to first heat?
The first visit is for looking and measuring: the house, the ducts, the venting, the gas supply and where the furnace sits. You then get a written price for the furnace and the work, and nothing is ordered or removed until you approve it. If a central air conditioner shares the furnace's air handler, its age is noted too, since air conditioning installation is sometimes worth timing with the furnace.
On installation day the old furnace is disconnected and taken out, the new one is set in place, and the gas line, venting, condensate drain and wiring are connected. The furnace is then started, run through full heating cycles and checked for safe combustion. Work is performed by TSSA-certified gas technicians. You are shown the thermostat, the filter and the furnace switch, and given the manufacturer's paperwork; registering the furnace with the manufacturer and keeping up yearly maintenance are usually what keep its warranty valid.
If your property is rural, especially above the escarpment, it may not be on a natural gas main and may use propane or oil. Please confirm the fuel when you get in touch, because the furnace, the venting and the connections differ with it. A quote request is a good place to start.