Quick Answer
Replacing a gas furnace in Ottawa typically costs $3,500 to $8,000 installed in 2026, and most homeowners pay about $4,500 to $6,000. Your price depends on the furnace’s size and features, the condition of your ductwork, and how complex the installation is.
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In Ottawa, a furnace isn’t a luxury — it runs for months every winter. So when yours is getting old or breaking down, the first question is usually what a replacement will cost. Here’s a clear breakdown to help you budget.
Average Furnace Replacement Cost In Ottawa (2026)
A new gas furnace in Ottawa typically costs $3,500 to $8,000 installed, with most homeowners paying about $4,500 to $6,000 including installation, permits and removal of the old furnace. Where your home lands depends on the furnace’s size and features, and what the installation involves.
| Gas Furnace | Typical Installed Cost | Good To Know |
|---|---|---|
| Standard single-stage | $3,500–$6,500 | Meets Canada's 95% AFUE minimum |
| Premium two-stage or modulating | $5,500–$8,000 | Quieter, more even heat, often up to 98% AFUE |
Furnace Replacement Cost By Fuel Type
| Furnace Type | Typical Installed Cost | Good To Know |
|---|---|---|
| Natural gas | $3,500–$8,000 | The most common choice in Ottawa |
| Electric | $3,000–$5,000 | Cheaper upfront, but usually costs more to run |
| Oil | $4,000–$7,000 | Less common today, mostly in older homes |
What Affects The Cost Of A New Furnace
1. The right size for your home
A furnace should be sized to your home — its square footage, insulation, windows and layout — not just matched to the old unit. A furnace that’s too big or too small costs more to run and wears out faster.
2. Features
Furnaces with two-stage or modulating burners and variable-speed blowers cost more upfront, but they heat more evenly and run more quietly. Basic single-stage models sit at the lower end of the range.
3. Ductwork condition
Homes with ductwork in good shape keep installation costs down. If ducts need repairs or replacement, that can add $1,000 to $3,000 to the project.
4. Installation complexity
Older homes with outdated heating systems may need updates to venting, gas lines or electrical to accommodate a modern furnace. Switching fuel types adds cost too.
Furnace Efficiency In Canada
Efficiency is measured by AFUE — the share of fuel that becomes heat for your home. In Canada, new gas furnaces must be at least 95% AFUE, so every new gas furnace is already a high-efficiency model.
That means the real choice isn’t between efficient and inefficient furnaces — it’s about size, features and warranty. If you’re replacing a 20-year-old furnace, even a standard new model will use noticeably less fuel.
Rebates And Financing
Energy-efficiency rebate programs change often, and eligibility depends on your home and the equipment. Ask us what’s currently available when you request your quote. Colair also offers financing through Financeit, so you can spread the cost over flexible monthly payments.
How To Choose The Right Furnace For Your Home
- Fuel type. Most Ottawa homes use natural gas, but some use electricity or oil.
- Proper sizing. Ask how the contractor sized the furnace. It should be based on your home, not your old unit.
- Features. Decide whether quieter, more even heat from two-stage or variable-speed equipment is worth it to you.
- Warranty. Every manufacturer’s warranty is different. Compare them side by side, including what’s covered for parts and labour.
- Maintenance. Plan for a yearly tune-up to protect your warranty and keep the furnace running efficiently.
When Is It Time To Replace Your Furnace?
Most furnaces last 15 to 20 years, depending on the type, how well they’re maintained and how hard they work. Signs it may be time for a new one:
- Frequent repairs. When repair bills keep adding up, replacement is often the better value.
- Uneven heating. Cold rooms or temperature swings can mean the furnace is struggling.
- Rising energy bills. Older furnaces lose efficiency and use more fuel over time.
- Unusual noises or odours. Banging, rattling or strange smells can point to serious internal problems.
- Age. If your furnace is 15+ years old and needs a major repair, it’s worth pricing a replacement.
Timing Matters
Replacing your furnace in the spring, summer or early fall gives you time to choose the right system — instead of rushing an emergency install in the middle of an Ottawa winter.
The Bottom Line
In 2026, replacing a gas furnace in Ottawa typically costs $3,500 to $8,000 installed, with most homeowners paying about $4,500 to $6,000. Size, features, ductwork and installation complexity decide where your home lands. A properly sized furnace, installed before the old one fails, will keep you comfortable for the next 15 to 20 winters.
Learn more about our furnace replacement service, or if you’re also thinking about cooling, see what central air costs. Not sure it’s time yet? Read repair or replace your furnace.
Source: Ottawa Contractors — Furnace Replacement Cost Ottawa. Gas furnace prices reviewed September 2026.
