The thing stopped working. Or it's making a sound it definitely wasn't making last winter. Either way here you are. Furnace replacement Ottawa homeowners deal with every year, and yet almost nobody knows what the process looks like until they're standing in a cold basement at 7am googling "how long does this take."
Ottawa Winters Don't Care About Your Timeline
Seriously. -20°C and dropping, and your furnace decides that's a great time to give up. It happens more than people realize the cold snaps put pressure on already-struggling systems, and that's when things finally break.
Most furnace failures aren't surprises, though. Not really. There were signs of weird smells, one room that never got warm, a gas bill that kept creeping up for no obvious reason. If the system's pushing 15–20 years, an HVAC upgrade wasn't a maybe, it was a when. Ottawa's winters just have a way of deciding the timeline for you.
First Thing: Someone Has to Come Look at It
You call a heating contractor Ottawa trusts, and the first visit isn't the installation. It's an assessment. A decent contractor won't quote you over the phone without seeing the setup, the existing venting, the ductwork condition, clearances around the unit, and what the electrical situation looks like. That visit matters. A lot. Get the furnace size wrong too big, too small and you'll feel it for years. Oversized units short-cycle, undersized ones run constantly. Neither is good. The visit takes maybe 45 minutes. Use it. Ask what brands they carry. Ask about efficiency ratings. Ask whether your ductwork needs any work before the new unit goes in. If a contractor's answers feel vague or rushed, that's information too.
Picking the Unit: Efficiency Actually Matters Here
After the assessment, the contractor lays out options. Modern residential heating systems generally come in two tiers: standard efficiency (around 80% AFUE) and high-efficiency (90–98% AFUE). Higher AFUE means less gas burned for the same amount of heat. High-efficiency costs more upfront. That's just true. But in Ottawa, running a furnace hard for six or seven months a year, the monthly savings add up. A lot of homeowners see that gap close within 5–8 years, sometimes faster if they're replacing something from the early 2000s that was never that efficient to begin with. Worth asking about rebates too. Ontario has had programs tied to high-efficiency equipment; a good contractor knows what's active and handles the paperwork. Sometimes it's a few hundred dollars, sometimes more.
Removal Day: The Unglamorous Part
Two technicians show up. The old unit comes out first. That part alone can take anywhere from 45 minutes to a couple of hours depending on the age of the system, how the venting was set up, whether there's a masonry chimney involved. That last one matters. Older furnaces were often vented through brick chimneys. High-efficiency units vent through PVC pipes run to an exterior wall. That switch means new penetrations through the foundation or rim joist. Standard procedure but it adds time, and it changes the look of things outside. The removal phase is unglamorous. But a sloppy removal creates problems downstream. Watch for whether the crew protects the floors and cleans up as they go. That's not a small thing.
The Install: This Is the Main Event
The new furnace installation on a standard residential job takes roughly 3–5 hours once removal is done. The crew gets the unit positioned, connects it to the gas line, runs the venting, handles the electrical, ties into existing ductwork or modifies where needed and sets up the new thermostat if that's part of the scope.
A few specifics worth knowing going in:
- Gas lines get pressure-tested before the system fires up not optional, not negotiable
- New PVC venting has to be properly sloped and secured sagging pipes cause condensate issues later
- If the ductwork connections need sealing or adjusting, that happens now
The crew should be cleaning up as they work. If they're not, say something.
Commissioning: Don't Let Them Skip This
Here's where some installations fall short. Once the system is running, it needs to be properly commissioned not just switched on and declared done. Commissioning means actually checking things. Gas pressure at the manifold. Temperature rises across the heat exchanger. Airflow and static pressure in the duct system. Carbon monoxide readings. Thermostat calibration. All of it. Ask to see what they're measuring. Any solid heating contractor Ottawa homeowners rely on will walk through this without hesitation. If the tech seems annoyed by the question, that's worth noting.
Permits Yes, They're Required
Ottawa requires a mechanical permit for furnace replacements. The contractor pulls it that's their job, and it should be part of what you're paying for. A city inspector will follow up at some point after the installation to confirm everything meets Ontario's building code. Don't skip this part. An uninspected installation can create headaches with home insurance and shows up as a problem during resale.
What Does Furnace Replacement Actually Cost in Ottawa?
Straight answer: most complete jobs run between $3,500 and $7,500. Furnace replacement cost swings based on which unit gets installed, whether the venting needs a full reconfiguration, and if there's any ductwork that needs attention. High-efficiency units with variable-speed motors are at the top of that range. Basic single-stage equipment costs less. Both are real options depending on the home and the budget. Get two quotes minimum. Not to pit contractors against each other just to make sure the scope of work being described is actually comparable. A quote that's significantly lower almost always means something's missing. Find out what.
FAQs
How long does furnace replacement take?
Most jobs run 4 to 8 hours from start to finish. Simple swaps with no venting changes come in on the shorter end. Anything involving a chimney-to-PVC venting switch, older ductwork that needs adjusting, or tricky basement layouts can stretch toward a full day. The home won't have heat during the work, so plan around that.
What happens during a furnace installation?
The old unit gets pulled out, the space gets prepped, and the new furnace goes in connected to the gas line, electrical, ductwork, and new exterior venting. Once it's physically in place, the system gets pressure-tested, fired up, and commissioned properly: airflow, gas pressure, heat output, CO levels, thermostat function all checked before the crew leaves.
How much does a new furnace cost in Ottawa?
Expect to pay somewhere between $3,500 and $7,500 for a full replacement in Ottawa, equipment and labour included. High-efficiency models cost more upfront but cut into monthly gas bills over time. Always get the installed price in writing not just the equipment number and confirm whether the permit fee is baked in or extra.
Can I replace my furnace in winter?
Yes and honestly, most replacements happen in winter because that's when systems fail. Good contractors build capacity for emergency calls and can usually get there within 24 to 48 hours. The home will be without heat for several hours during the job, so make arrangements if there are young kids, elderly family members, or pets in the house.