You know the morning. It’s been warm for weeks, you’ve barely thought about the furnace since spring, and then one day you wake up and the house is freezing. You shuffle over to the thermostat, switch it to heat, and wait for that familiar hum.
Usually it comes. Sometimes it doesn’t.
Every fall, our phones light up with calls from people around Kitchener-Waterloo whose furnaces picked the first cold morning of the year to act up. A weird smell. A bang when it starts. A fan that runs but blows cold air. Or just silence.
We’ve been doing this long enough to know that most of those calls could have been avoided. That’s why we wrote this. It’s the stuff we find ourselves explaining to customers every week, whether we’re in a basement in Waterloo or out in one of the smaller communities around the region. None of it is complicated. It just helps to know it before winter shows up.
Why fall is the time to deal with it
Furnaces don’t break on nice days. They break when it’s bitterly cold, the wind is whipping, and it’s the middle of the night. That’s not a coincidence. Your furnace works hardest when it’s coldest, and a part that’s been limping along will usually pick that moment to give out.
If we find a tired igniter in October, it’s a quick fix at a time that suits you. If that same igniter quits during a January deep freeze, you’re dealing with a cold house, maybe worried about your pipes, and waiting on a service call along with half the city.
There’s also the fact that your furnace has been sitting idle all summer. Dust piles up on the burners. Parts that haven’t moved in months get sticky. Once in a while we’ll even pull a mouse nest or a bit of a bird’s nest out of the venting. Better we find that now.
And, honestly, it’s just easier to get an appointment in the fall. Once the first real cold snap hits, every heating company in the area is running flat out.
How your furnace works (the short version)
You don’t need to know this to own a furnace, but it makes the rest of this guide a lot easier to follow. Most homes around here run on a natural gas forced-air furnace, so that’s what we’ll walk through.
When the house cools down past whatever you’ve set on the thermostat, the thermostat sends a signal to the furnace. The first thing that happens is a small fan, called the inducer motor, starts up to clear out any old exhaust and get air moving up the vent. A little safety switch makes sure the vent is drawing the way it should before the furnace goes any further.
Then the igniter heats up. On most newer furnaces, it’s a small ceramic piece that glows red-hot. The gas valve opens, the burners light, and a thin metal rod called the flame sensor checks that there’s actually a flame. If there isn’t, the furnace cuts the gas right away. It’s a good safety feature and one of the most common reasons a furnace shuts down.
The burners heat a sealed metal box called the heat exchanger. After a moment, the big blower fan kicks on and pushes the air from your house across that hot metal and back out through your ducts.The exhaust from the burners stays separate and goes outside, either up the chimney or through those white plastic pipes you see on the side of a lot of houses.
So there are quite a few parts working together every time your heat comes on. Any of them can get dirty, wear down, or fail. That’s really the whole reason furnace service exists.
Signs something’s not right
Furnaces tend to give you a heads-up before they quit completely. You just have to catch it.
New noises: A furnace in good shape is pretty quiet. You’ll hear a soft whoosh when it lights and a steady hum from the fan. That’s about all. A bang or boom when it starts up is a big one. It usually means gas is building up for a split second before it lights. That little explosion is rough on the heat exchanger, so don’t ignore it. Squealing often means a motor bearing or belt is on its way out. Rattling could be a loose panel, which is no big deal, or something more serious inside. And if you hear clicking over and over but the burners never catch, the furnace is trying to light and can’t.
It keeps starting and stopping: If the furnace runs for a minute, shuts off, and then starts again a few minutes later, that’s called short cycling. It wastes gas and wears everything out faster. A dirty flame sensor and a clogged filter are the usual suspects, but it can also be the thermostat, or a furnace that’s simply too big for the house.
Some rooms are warm, some aren’t: We hear this constantly. The living room is comfortable and the back bedroom is an icebox. Sometimes that’s the furnace struggling. Sometimes it’s the blower. And a lot of the time, especially in older homes, it’s ductwork that was never quite set up right. It’s usually something we can improve.
The gas bill jumped: If you haven’t changed how you use the house and your bill keeps going up, your furnace might be losing efficiency. When it’s dirty or out of adjustment, it has to run longer to do the same job. A proper tune-up often brings things back in line.
A yellow flame: If you can see the burners, the flame should be steady and blue. If it’s yellow, orange, or lazy and flickering, the gas isn’t burning cleanly. That can mean dirty burners, a bad air mix, or a venting issue, and unclean burning is how carbon monoxide gets made. That’s a call-someone situation.
Odd smells: A dusty, slightly burnt smell for the first few hours after you turn the heat on is normal. It’s a summer’s worth of dust burning off, and it fades. If it sticks around, or if you smell something electrical or like melting plastic, that’s not normal.
If you smell gas: If you smell rotten eggs, that’s the scent added to natural gas so people can tell when it’s leaking. Get everyone out of the house. Don’t touch light switches or anything that might spark. Once you’re outside, call your gas company’s emergency line or 911. Don’t stay behind trying to figure out where it’s coming from.
More dust than usual: Your furnace moves all the air in your house through it, over and over, all day. If the filter is packed or the ducts are dirty, you’ll see it on the furniture and probably feel it in your nose. If your allergies seem to act up the same week the heat comes on, that’s a hint.
It won’t turn on at all: Before you call anyone, check the easy stuff. We’d honestly rather you save the money if it’s something simple. Make sure the thermostat is on heat and set higher than the room temperature. Try new batteries if it takes them. Find the furnace power switch, which usually looks like a normal light switch on or near the unit, and make sure it’s on. Check your breaker panel. And make sure the front cover of the furnace is on snug, because most furnaces won’t run if it’s loose.
Still nothing? Then it’s time to give us a call.
The repairs we see all the time
Do this long enough and you start seeing the same problems every season.
Dirty flame sensors. If we had to pick the single most common furnace call, this might be it. Carbon builds up on the sensor, it can’t tell the flame is lit, and the furnace shuts off a few seconds after starting. Often a good cleaning sorts it out. Sometimes it needs replacing.
Igniters that have had enough. They heat up and cool down thousands of times, and eventually they crack or burn out. No igniter means no flame. It’s a common and usually quick repair.
Snowed-in or iced-up vents. This is a big one around here. High-efficiency furnaces vent through plastic pipes out the side of the house, and after a heavy snowfall or freezing rain those pipes can get buried or frosted over. The furnace senses the blockage and won’t run. After every big storm, we get a wave of these calls. If you’ve got those pipes, please take a minute to clear them after it snows.
Blower motors and capacitors. If the fan hums but won’t turn, the capacitor that helps it start is often the problem. Motors wear out too, especially if they’ve been pushing air through a dirty filter for a long time.
Control boards. This is the brain of the furnace. Power surges, moisture, and wear can all knock one out, and the symptoms can be all over the place. It takes experience to figure out whether it’s really the board or something else.
Thermostats. Every now and then we show up and there’s nothing wrong with the furnace at all. It’s the thermostat. Loose wiring, dead batteries, a faulty sensor, or a thermostat mounted somewhere silly, like next to a heat vent or a drafty window, can all make the furnace look like it’s misbehaving.
Condensate drains. High-efficiency furnaces produce water as part of normal operation, and it drains away through a small trap and hose. If that line clogs or freezes, the furnace shuts itself off. We see this a lot when the furnace sits in a cold corner of the basement or a crawlspace.
Cracked heat exchangers. This is the one nobody wants to hear about. A crack can let exhaust, including carbon monoxide, into the air circulating through your home. It’s usually the priciest part in the furnace, and finding a crack is often the point where we start talking about replacement. It’s also why we check the heat exchanger carefully every single time we service a furnace.
What a proper tune-up looks like
We’ll just say it. Some places advertise a “tune-up” that’s really a filter change and a quick look around. That isn’t a tune-up.
When one of our techs services your furnace, they go through the whole thing. They look over the heat exchanger for cracks or rust. They clean the burners and check the flame. They clean and test the flame sensor and check the igniter for wear. They measure the gas pressure and set it where the manufacturer says it should be.
They’ll run a combustion test and check for carbon monoxide so we know it’s burning cleanly and safely. They inspect the venting for blockages, leaks, and proper slope. Every safety switch gets tested. The blower gets cleaned and checked, including how hard the motor is working and whether the capacitor is still healthy. Electrical connections get looked at and tightened. On high-efficiency furnaces, the condensate drain gets flushed. They’ll check that the thermostat is reading and working properly, and they’ll look at or change the filter. Then they’ll let the furnace run through a full cycle, start to finish, to make sure everything happens the way it’s supposed to.
It takes a bit longer to do it right. But that’s how you catch the little stuff before it turns into a no-heat call on the coldest night of the year.
Is yearly maintenance worth the money?
Fair question. Nobody loves paying for something when it seems to be working fine. But in our experience, it usually pays for itself.
You get fewer breakdowns. A big chunk of the emergency calls we go on are for problems that would have shown up during a routine service. You’ll likely spend less on gas too, because a clean, properly adjusted furnace uses less fuel to keep the house warm. Over a long winter, that adds up.
You’ll also get more life out of your equipment. A furnace that’s looked after simply holds up better than one that’s ignored, and replacing a furnace is not a small bill. And if your furnace is still under warranty, a lot of manufacturers want proof of regular professional maintenance before they’ll cover a repair. Skipping it could leave you paying for something that should have been covered.
But really, the biggest reason is safety.
About carbon monoxide
Your furnace burns fuel inside your home. When everything’s working right, the exhaust goes outside and you never give it a second thought. When something’s wrong, carbon monoxide can end up in the air you’re breathing, and you won’t see it, smell it, or taste it.
Early symptoms feel a lot like the flu: headaches, dizziness, nausea, feeling run down, shortness of breath. A telltale sign is feeling better when you leave the house and worse when you come home. Another is when everyone in the house, pets included, seems to be sick at the same time.
In Ontario, if your home has a fuel-burning appliance, a fireplace, or an attached garage, you’re required to have working CO alarms. Put them outside every bedroom area, test them once a month, and replace them when they reach the end of their life. There’s usually a date printed on the back. If one goes off, get everyone outside into fresh air and call 911.
The yearly inspection is how you prevent carbon monoxide problems. The alarm is your backup in case something gets missed. You want both.
One more thing. We’re all for homeowners changing their own filters and clearing their vents. That stuff helps a lot. But anything involving the gas line, the burners, or the combustion side of the furnace needs a licensed gas technician in Ontario. We know online videos make it look simple. Gas is not something to experiment with.
Simple things you can do yourself
You don’t need a tech for everything. A few small habits go a long way.
Change your filter. If you only do one thing from this whole article, make it this one. Check it regularly through the heating season and swap it when it looks dirty, and check it more often if you’ve got pets, allergies, or a renovation going on. A clogged filter chokes the furnace, makes it overheat, burns more gas, and wears everything out faster.
Leave your vents open. Don’t push the couch up against a return vent or throw a rug over a floor register. And try not to close off a bunch of vents in rooms you don’t use. It seems like it should save money, but it can throw off the pressure in your ducts and make the furnace work harder. Clear those outdoor pipes. We keep bringing this up because it’s such a common call. After it snows, go take a look at the vent pipes on the side of your house and make sure they’re clear.
Give the furnace some room. Don’t store paint, gas cans, cleaners, or stacks of boxes right next to it. It needs air around it, and our techs need room to work.
Pay attention. You live there every day. If something sounds different, smells different, or just feels off, it’s worth a call.
If you don’t already have one, a programmable or smart thermostat is worth considering too. Dropping the temperature a few degrees overnight or while you’re at work saves real money without making the house uncomfortable.
Repair it or replace it?
Every furnace eventually reaches the point where fixing it stops making sense. There’s no magic formula for figuring out when you’ve hit that point. It’s more of a gut check based on a few things. How much the repair costs. A lot of people in the trade go by a simple rule of thumb: if the repair is going to cost more than about half the price of a new furnace, and your current one has already been through a lot of winters, replacing it is usually the smarter money. How often it’s been breaking down. One repair here and there is normal. Several repairs over the last couple of winters is a pattern, and patterns tend to keep going.
How efficient it is. Older furnaces can waste a surprising amount of the gas you pay for. Today’s high-efficiency models turn 95 percent or more of their fuel into heat for your home. You feel that difference on every bill.
How comfortable your home is. If you’re putting up with cold rooms, dry air, or big temperature swings, newer equipment with variable-speed fans and modulating burners can make the house feel completely different.
Safety. If an older furnace has a cracked heat exchanger, that usually answers the question for you. Whatever the case, we’ll give you the options straight. If repairing makes more sense than replacing, that’s what we’ll tell you. No upselling, no scare tactics. That’s what “No Bull, Just Moose” is all about.
If you’re ready for something new
If it does turn out to be time for a new system, the options today are a lot better than they used to be.
Modern high-efficiency gas furnaces are quieter and more comfortable than older ones. Two-stage and modulating models spend most of their time running gently in the background, so you get steadier temperatures instead of a blast of hot air followed by a chill.
Cold-climate inverter heat pumps have really changed things around here. For years, people assumed heat pumps couldn’t handle an Ontario winter. The newer inverter models heat efficiently well below freezing, and they cool your home in the summer too, so it’s two systems in one. This happens to be something we know inside out. Able Air has been the number one Amana inverter heat pump dealer in Canada for several years running, and we rank in the top 15 in North America.
For many homes, the best of both worlds is a hybrid or dual-fuel setup. The heat pump takes care of the milder days and the furnace kicks in automatically when it gets really cold. You burn a lot less gas and still have dependable heat for the worst of January.
We carry full lines from Amana and Lennox, and we’ll help you sort out what fits your home and your budget. Rebates and incentive programs for efficient equipment change from time to time, so just ask us what’s available when you’re ready to look. And if you’d like to see the equipment in person, drop by our showroom at 1501 Victoria St N in Kitchener.
Who we are
We’re Able Air, and we’re proud to serve homeowners across Kitchener-Waterloo and the surrounding areas.
We’re local. We work in the same kinds of homes you live in, from older houses with quirky ductwork to brand-new builds, and we know exactly what our winters put a furnace through.
We pick up the phone around the clock. Furnaces don’t care what time it is, so we offer 24-hour service. If your heat goes out at 3 a.m., you’ll talk to a real person.
And we try to be straight with people. Clear pricing, honest advice, and no pushing equipment you don’t need. We’ve picked up some industry awards along the way, and we’re proud of that, but mostly we just want to do the job right and have you call us again next time.
Questions we get a lot
How often should my furnace be serviced?
Once a year. Early fall is best, before you really need the heat.
How long does a tune-up take?
Usually about an hour to an hour and a half, depending on the furnace and what we find.
There’s a burning smell when I first turn the heat on. Should I worry?
For the first few hours of the season, no. That’s just dust burning off. If it doesn’t go away, or if you smell gas or hot plastic, call us.
Why is my furnace blowing cold air?
Start with the thermostat. If the fan is set to “on” instead of “auto,” it’ll blow air even when the burners aren’t running. Then check the filter, since a clogged one can make the furnace overheat and shut the burners off. If it’s neither of those, it could be an ignition problem or a blocked drain line, and that’s where we come in.
Do you service my area?
We cover Kitchener-Waterloo and the surrounding areas. If you’re not sure whether you’re in our range, just give us a call and ask.
Can I fix my furnace myself?
Filters, thermostat settings, and clearing outdoor vents, absolutely. Anything involving gas or the burners needs a licensed gas technician.
Don’t wait for the first freezing night
If you take one thing away from all this, let it be this: an hour of attention in the fall beats a cold house and an emergency call in January every time. Whether you want a tune-up, need something fixed, or just want to talk through whether it’s time to upgrade, we’d be glad to help. We serve Kitchener-Waterloo and the surrounding areas. And if your heat goes out after hours, don’t sit there waiting for morning. We’re here 24/7. Stay warm out there. Book your furnace tune-up or repair today by calling 519.954.7300.
