Should you repair your furnace or replace it?

First, understand the proposed repair

Before comparing prices, ask the contractor to identify the failed part and explain the evidence behind the diagnosis. Separate work needed to restore operation from optional maintenance or upgrades. If the quote names several parts, ask which are confirmed failures and which are preventive replacements.

For a furnace, useful questions include: What was tested? Is the problem confined to the part being replaced? Is there a combustion, venting or heat-exchanger concern that needs a separate assessment? Request the findings in writing; a price calculator cannot resolve a safety question.

Have the model number, approximate installation date, service history and warranty paperwork available. Ask the manufacturer or contractor whether any parts are covered, and whether you still owe labor or diagnostic charges.

Compare the whole job

Use the total installed price before rebates and financing. Ask for missing items to be priced explicitly so one quote does not look cheaper just because it leaves work out.

• Repair: named parts, labor, diagnostic fee, tax, and the warranty on this work.
• Replacement: exact furnace model, installation labor, removal of the old unit, and tax.
• Any proposed venting, gas-line, electrical, thermostat or duct changes: are they included, excluded, or subject to a later inspection?
• Permits, commissioning, completion date and separate parts and labor warranty terms.

ENERGY STAR identifies a furnace older than 15 years, frequent repairs, rising bills and comfort problems as reasons to discuss replacement or system improvements with a contractor. That is a prompt for an assessment, not an expiration date. Read the replacement guidance.

If some rooms are uncomfortable, ask how the proposal addresses that specific problem. Replacing the furnace is a different scope from changing ducts or improving insulation. Request an explanation of which work is expected to help and why.

A worked comparison

Use the calculator to compare your own written quotes. Its percentage bands are editorial rules of thumb, not a validated engineering standard. Without a replacement quote, it shows an example and asks you to get a real price.

Free to use. Your quote amounts stay in your browser.

Questions to take to your contractor

1. What evidence supports the diagnosis, and what would remain unresolved after this repair?
2. Does the repair include every charge needed to restore operation?
3. What home assessment supports the proposed replacement size?
4. Which warranty costs would I still be responsible for?
5. If I keep the furnace, what should I monitor and when should it be assessed again?

If you heat with oil and are considering changing equipment, compare running costs in the heat pump versus oil calculator. Use your actual fuel and electricity prices; the repair comparison does not include those savings.

Sources and limits

Official guidance supports the general considerations here. The checklist and worked example are FrugalWatt's editorial aids; the linked organizations have not endorsed them. Source pages were read September 10, 2026 with AI assistance.

• ENERGY STAR: replacement considerations
• ENERGY STAR: hiring an HVAC contractor

This page does not diagnose equipment, certify safety or promise savings. Have urgent faults assessed before using price comparisons. Incentive eligibility and any older financial figures on source pages need a current program check; this guide does not rely on them.

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