Homeowner decision guide

Furnace repair or replace: put safety and venting first

A furnace decision may involve an ordinary component failure or a potential gas, combustion, or carbon-monoxide hazard. If a professional reports a safety concern, pause the price comparison and obtain the appropriate qualified assessment. Otherwise, compare the written repair with a complete installed replacement scope.

What changes the answer?

Ask what test identified the failed part and whether the repair would address the cause rather than only the symptom.
Check whether the furnace or its components are covered by a manufacturer or installer warranty; record only confirmed coverage.
A replacement bid should address venting, combustion testing, duct connections, gas and electrical work, and permits, not just the furnace cabinet.

Check the written proposal

Look for these items in each quote. If one is missing, ask whether it is excluded or will be priced later.

Equipment model and capacity with sizing basis
Venting, gas, electrical, and duct connections
Permit, combustion tests, removal, disposal, and labor warranty

Questions to take back to the contractor

Is there any documented gas, venting, heat-exchanger, or carbon-monoxide concern?
What diagnostic test supports replacing the whole furnace instead of repairing the part?
Which venting or duct changes are included in the total?

Compare your real numbers

Enter the repair quote now, even if you do not yet have a replacement price. Add up to three complete proposals later and keep their rebates and scope separate.

Use the free worksheet

What this cannot determine

The worksheet never decides whether a furnace is safe. A possible hazard overrides its financial output. Age and past repairs add context but do not become a made-up failure probability.

Sources

Reviewed September 2026. Program eligibility and local requirements should be confirmed before approving work.