As the days grow shorter and the crisp autumn air signals the end of another beautiful Ottawa summer, a homeowner’s attention naturally shifts indoors. Before the first major snowfall, it’s crucial to have confidence in your home’s most vital winter appliance: the furnace. But you don’t have to wait for a problem to arise to assess its health. Learning how to check if furnace is working properly is a valuable skill that can save you from inconvenient breakdowns, costly repairs, and high energy bills.
This homeowner’s checklist is designed to guide you through a simple, observational check-up of your furnace. It’s not about performing complex repairs, but about using your senses to spot the early warning signs of a problem. If anything on this list raises a concern, you’ll know it’s time to call a professional before the deep freeze sets in.
The 5-Sense Furnace Check: What to Look, Listen, and Smell For
You can learn a lot about your furnace’s condition just by paying close attention. This simple “five-sense” walk-through is your first line of defence in spotting trouble.
The Visual Inspection (What to LOOK For)
- The Colour of the Flame: If you have a gas furnace, you may be able to see the burner flame through a small viewport. A healthy furnace flame should be a steady, consistent blue. If the flame is yellow or orange, or if it flickers and dances erratically, it’s a sign of a problem, such as dirty burners or incomplete combustion.
- The Surrounding Area: Look at the floor and walls around the furnace. Are there any black soot marks, rust streaks, or signs of water pooling or leaking? Soot can indicate a ventilation issue, while water can mean a problem with the condensate line (on high-efficiency models) or a leak.
- Your Vents and Registers: Walk through your home and ensure that none of your supply or return air vents are blocked by furniture, rugs, or boxes. Blocked vents can severely restrict airflow and strain your entire system.
The Sound Check (What to LISTEN For)
- Normal Sounds: A healthy furnace should operate relatively quietly. You’ll hear the gentle “whoosh” of the burners igniting and the steady hum of the blower fan distributing air.
- Problem Sounds: You should listen for any new or unusual noises:
- Loud Banging or Popping: This often points to dirty burners causing a delay in ignition, resulting in a small gas build-up that bangs when it finally lights.
- High-Pitched Squealing: This typically indicates an issue with the blower motor belt or bearings.
- Rattling or Vibrating: This could be as simple as a loose access panel, but it could also signal a more serious issue with the motor or internal components.
The Smell Check (What to SMELL For)
- Normal Smells: It’s normal to smell a faint, dusty burning odour the first one or two times you turn your furnace on for the season. This is just dust burning off the heat exchanger.
- Problem Smells: Other odours are immediate red flags:
- Rotten Eggs / Sulfur: CRITICAL WARNING. This smell is added to natural gas to signal a leak. If you smell this, do not touch any light switches or electronics. Leave your home immediately and call your gas utility (Enbridge Gas in Ottawa) from a safe distance.
- Burning Electrical or Rubber: If you smell something like burning plastic or overheated wiring, it could be a failing motor or an electrical fault. Shut the furnace off at the circuit breaker immediately and call a technician.
The Performance Test: How to Check if Furnace is Working Properly
After a sensory check, you can perform a simple test to see how the system responds. This is a key part of learning how to check if furnace is working properly.
The Thermostat Test
This is the most basic functional test. Go to your thermostat and switch it to the “Heat” setting. Turn the temperature up by 5°C from the current room temperature. This should send a signal to your furnace to begin its heating cycle. Listen carefully. Within a minute, you should hear a sequence of clicks and the hum of the inducer motor, followed by the “whoosh” of the burners igniting. A minute or two after that, the main blower fan should start pushing warm air through your vents. If this sequence doesn’t happen, or if it starts and then stops, there is an issue with the startup cycle.
Check the Furnace Filter
A clogged filter is the number one cause of furnace problems. It restricts airflow, forcing the system to work harder, which can lead to overheating and shutdowns. Find the filter slot on your furnace (usually a 1-inch slot on the side or bottom). Slide the filter out and hold it up to a light. If you can’t see light through it, it’s clogged and needs to be replaced immediately. In Ottawa’s climate, filters should be checked monthly during the winter.
Examining the Condensate Line (For High-Efficiency Furnaces)
If you have a high-efficiency furnace (which most modern Canadian homes do), it will produce condensation as it operates. This water drains away through a clear plastic tube, usually to a floor drain. Check to ensure this tube is not clogged with algae or debris and that water is not backed up. A blockage can trigger a safety switch that shuts your furnace down to prevent water damage.
When Your Checks Point to a Problem
This checklist empowers you to identify the symptoms of a furnace problem. But what do you do with that information?
Why You Shouldn’t Ignore the Signs
It can be tempting to ignore a minor rattle or a slightly less effective heating cycle, but small problems in a furnace almost always grow into bigger, more expensive ones. Ignoring a problem can lead to a complete breakdown during an Ottawa cold snap, poor energy efficiency (costing you more on your Hydro Ottawa or Enbridge bills), and, most importantly, potential safety risks.
Calling in a TSSA-Certified Professional
This guide is for observation, not DIY repair. For your safety and to ensure compliance with Ontario’s strict regulations, any repair or maintenance work on a gas furnace must be done by a TSSA (Technical Standards and Safety Authority) certified technician. They have the diagnostic tools, training, and parts to safely and effectively fix the root cause of any problem you may have identified.
Conclusion: Be Proactive, Not Reactive
Regularly performing these simple checks is a proactive step every Ottawa homeowner can take. By knowing how your furnace should look, sound, and feel when it’s working correctly, you can spot trouble long before it becomes an emergency. Staying proactive with all of your home’s systems is key to avoiding costly emergencies. Just as you monitor your furnace, it’s also important to know the signs for other appliances, like learning when to replace your hot water tank before it fails.
If your own check fails or raises concern, schedule a professional inspection and tune-up before winter truly arrives.