When a furnace breaks down, the first question is whether to fix it or replace it. There's no universal answer — it depends on the unit's age, the cost of the repair relative to a new system, and whether the failure is a safety issue. Here's a straightforward way to think it through.
Age is the biggest factor
A well-maintained gas furnace typically lasts 15–20 years. If yours is under about 10 years old and the repair is reasonable, fixing it is usually the right call. Past 15 years, parts get harder to find, efficiency has slipped, and you're often one cold snap away from the next breakdown — so money spent on repairs is money you won't get back.
Weigh the repair cost against the system's value
A common rule of thumb: if a single repair costs more than about a third of a new system, replacement usually makes more sense — especially on an older unit. We'll always give you the honest repair-vs-replace recommendation in writing, with the actual numbers for your situation, so you're not guessing.
Comfort and efficiency clues
- Rooms that never feel evenly heated, or a furnace that runs constantly to keep up.
- Rising gas bills with no change in the weather or your habits.
- Frequent repairs — two or more in the last couple of winters.
- A unit that's loud, or cycles on and off rapidly.
When replacement isn't optional
Some failures are safety issues, not comfort ones. A cracked heat exchanger can leak combustion gases, including carbon monoxide, into your home's air — that furnace gets shut down and replaced, not repaired. The same goes for repeated safety lockouts a technician traces back to a failing exchanger. If a tech flags this, take it seriously.
If you're leaning toward replacement, it's also worth asking about a heat pump or a heat-pump-plus-furnace setup — they can lower your operating costs and may qualify for current rebates.
Want a straight answer for your home?
We give you a written price before any work starts — the estimate is free and there's no obligation.
