Start with which part failed, not with the age
Age alone is a poor guide and it is the thing salespeople reach for first. A twenty-year-old furnace with a failed igniter is a small repair on a machine that may well run another five years. A furnace with a cracked heat exchanger is a different conversation entirely, whatever its age.
What actually decides it is which component died and what it costs relative to the whole machine.
| What failed | Typical weight of it |
|---|---|
| Igniter, flame sensor, thermocouple, thermostat, pressure switch | Small. Repair almost regardless of age. |
| Draft inducer motor, blower motor, control board, gas valve | Moderate. Repair unless the furnace is very old and something else is also marginal. |
| Heating elements and sequencers on an electric furnace | Usually moderate, part by part. |
| Cracked heat exchanger | Decisive. The furnace is finished. |
The questions worth asking yourself
How long do you intend to keep the house? Somebody selling in two years and somebody staying twenty should make different decisions, and nobody but you can answer it.
Has it failed before, and recently? One repair on an old system is unremarkable. Three in two winters is a pattern, and the pattern is usually telling you something.
Is anything else marginal? If the technician mentions a blower that is drawing high, an inducer that is getting noisy, or a heat exchanger that is aging, those matter to the arithmetic even if they are not what failed this week.
Can you still get parts? Some older furnaces use controls and gas valves that are no longer made, which makes some repairs impractical whether or not they are theoretically possible.
What a replacement quote should contain
If you do decide to replace, these are the things a quote ought to say plainly. A quote that does not say them is not one you can compare against another.
- The equipment, by model number, not just a brand and a tier.
- Whether the furnace alone is being replaced, or the air conditioner's indoor coil with it.
- What happens to the ductwork, and whether any of it is being altered.
- The permit, which office it comes from, and whether its fee is included or extra.
- Carbon monoxide alarms, where the Idaho amendment applies.
- Removal and disposal of the old equipment.
- What the warranty covers, and crucially whether labor is included or only parts.
Two prices, side by side
When the honest answer might be replacement, ask for the repair price and the replacement price in the same conversation, from the same visit. A replacement recommendation should come with the reason, such as a cracked heat exchanger or a failed part on a very old furnace, not instead of it. Getting a second quote on a new furnace is a reasonable thing to do whoever gives the first.
Related
Before you call covers what to check first. If the system has never worked properly since it went in, sizing and altitude may be more relevant than either repair or replacement.
No heat? Tell us what the furnace is doing.
Gas, electric and high-efficiency furnaces across Caldwell, Nampa, Middleton and Parma. Start with the symptom and your ZIP code.
You'll be asked for your ZIP code first, so your call reaches a technician who covers your area.