Maybe it’s louder than it used to be. Maybe your energy bills keep creeping up. Or maybe it just can’t keep up with Calgary’s cold anymore.
In this guide, we’ll cover the top 5 signs it’s time to replace your furnace — from rising repair bills to declining performance and safety concerns.
Sometimes repairs make sense. Other times, they’re just delaying the inevitable. Here’s how to know when replacing your furnace is the smarter (and cheaper) move.
Introduction
Furnaces don't last forever. Most limp along for 15–20 years before efficiency nosedives or parts start failing in rapid succession. But how do you know when it's time to stop fixing and start planning for replacement? Here are the top five signs your furnace is hinting (or screaming) it's ready for retirement.
1. Age: The Furnace Is Old Enough to Vote
Most furnaces live 15–20 years with regular maintenance. If yours is pushing that age, it's on borrowed time.
Older models use less efficient technology, costing you more every month.
Parts get harder to source as manufacturers phase out old lines.
Efficiency standards (and rebates) keep improving meaning new models often pay for themselves in savings.
Rule of Thumb: If your furnace is 15+ years old and the repair quote is more than 25% of replacement cost, start budgeting for a new unit.
2. Frequent (and Costly) Repairs
If your furnace tech knows your coffee order, that's a problem.
Multiple service calls each winter signal major wear and tear.
A single big repair (like a cracked heat exchanger or blower motor replacement) can cost 30–50% of a new furnace.
If you're stacking repair bills year after year, replacement often makes more financial sense.
3. Rising Energy Bills Without Explanation
Old furnaces lose efficiency as components wear out.
A dirty or weak blower, worn burners, or leaky heat exchanger can cause long run times.
You'll see this on your energy bill a steady increase even when winter temps haven't changed much.
New high-efficiency furnaces (95%+ AFUE) use less fuel and often include variablespeed blowers that cut electrical use too.
If your energy bills keep creeping up despite clean filters and annual service, the furnace is likely the culprit.
4. Uneven Comfort or Strange Noises
Comfort problems = system problems.
Uneven Heating
Cold bedrooms, overheated living rooms, or swings in temperature often point to an underperforming furnace.
Strange Noises
Banging, popping, grinding, or squealing are signs of failing components or duct pressure issues.
Constant Running or Short Cycling
Both waste energy and shorten equipment life.
While some issues are repairable, in an older furnace they often signal it's time to replace.
5. Safety Concerns: Cracked Heat Exchanger or CO Issues
This one's serious.
A cracked heat exchanger can leak carbon monoxide (CO) into your home.
Symptoms may include frequent headaches, nausea, or dizziness when the furnace is running.
Even if you have CO detectors, a confirmed crack is usually the end of the line for a furnace.
If a tech tells you the heat exchanger is cracked → replacement is the only safe option.
Bonus Sign: Rebates & Incentives Make It a Smart Time
Government rebates, utility incentives, and manufacturer promotions can tip the scale in favor of replacement. Sometimes you can save thousands by upgrading during rebate windows rather than sinking money into repairs.
Quick FAQs
Q: How long does a furnace replacement take?
A: Typically one day for a straightforward swap. Add time if ductwork, venting, or electrical upgrades are needed.
Q: What size furnace do I need?
A: It depends on your home's square footage, insulation, and design. Contractors should run a proper load calculation — not just "replace it with the same size."
Q: Should I replace AC at the same time?
A: Often yes. Matching systems can improve efficiency, and installation costs are lower when done together.
Conclusion
If your furnace is old, noisy, inefficient, or unsafe, replacement is the smart move. A new high-efficiency model will save money, improve comfort, and give you peace of mind for the next 15–20 winters.
At HVACHELP.pro, our mission is to empower Calgary homeowners with the knowledge and confidence to make informed decisions about their heating, cooling, and home maintenance needs. We cut through the jargon and provide clear, actionable advice so you can keep your home comfortable and efficient without the guesswork.
We believe that understanding your home's systems is key to smart homeownership. That's why we offer expert guides, cost insights, and professional tips designed to help you navigate everything from routine maintenance to major system upgrades.