A furnace repair call can cost $150–$600. A new furnace is $3,000–$5,000. So when a customer asks "should I repair or replace?", we take it seriously.
1. It's Over 15 Years Old
The average gas furnace lasts 15–20 years with proper maintenance. If yours is past 15 and starting to have problems, the math usually favours replacement — especially with how much more efficient new units are (96%+ AFUE vs 60–70% for older models).
2. Your Heating Bills Keep Climbing
Older furnaces lose efficiency as they age. If your gas bill has gone up significantly over the past few years without a change in usage, your furnace is likely working harder and wasting fuel.
3. It Needs Frequent Repairs
One repair every few years is normal. But if you're calling us more than once a heating season, you're throwing money at a dying machine. A good rule: if the repair costs more than half the value of the furnace, replace it.
4. Uneven Heating Throughout the House
Cold rooms, hot spots, the bedroom that's always freezing — this often means your furnace is struggling to distribute heat properly.
5. The Burner Flame is Yellow or Orange
A healthy gas furnace burns with a blue flame. Yellow or orange means incomplete combustion, which can produce carbon monoxide. This is a safety issue, not just an efficiency issue — call us immediately.
6. Excessive Dust or Dry Air
An aging furnace can't properly filter or humidify air. If you're noticing more dust than usual, or your family has more dry skin and sore throats in winter, your furnace's air handling capacity may be declining.
7. It's Getting Loud
Banging, popping, rattling, or squealing are not normal operating sounds. Some can be fixed (loose panels, worn belts). Others signal fundamental mechanical failure.
The Repair vs Replace Formula
Multiply the age of the furnace by the cost of the repair. If the result is over $5,000, replacement is almost always better.
Example: 14-year-old furnace × $450 repair = $6,300. Replace.
Example: 6-year-old furnace × $400 repair = $2,400. Repair.
Call DMS at 403-619-6614 for a free furnace assessment. We'll tell you honestly whether repair or replacement makes sense.
Owner of DMS Plumbing & Heating, serving Calgary with honest, expert plumbing and heating services.
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