Should I repair or replace it?

Almost every “should I fix it?” decision comes down to four questions. They are the same four this whole site is built around.

How to think about it

1. What is happening? One failed part, or general wear? A single leaking valve is not the same as a worn-out system.
2. What should I do? Get a diagnosis first, ideally in writing, and a price for both the repair and the replacement.
3. What will it cost? Compare the repair, the replacement, and the cost of repairing again.
4. Is it worth doing? Think about age, running costs, safety and, if you will sell, what a buyer will see.

What can you do?

Step 1: Is it a safety issue? If yes, safety wins over every rule below. Examples: a cracked furnace heat exchanger, signs of carbon monoxide, active gas smells, a roof that leaks onto electrical equipment, or a water heater leaking at the tank. Stop using it and call a qualified professional.

Step 2: How old is it compared with a typical lifespan? The NAHB life-expectancy study lists, for example: asphalt shingle roofs about 20 years, furnaces about 15–20 years, heat pumps about 16 years, central air conditioners about 10–15 years, and kitchen faucets about 15 years. ^[1] The study is from 2007 and says real lifespans depend on installation quality, maintenance, climate and use. Treat it as a rough yardstick.

Step 3: Compare costs. Two rules of thumb are widely repeated. They are not backed by a published study that we could find, so use them to start the conversation, not to decide:

• The 50% rule (rule of thumb). If the repair costs more than about half the price of replacing it, and the item is past about half its expected life, lean toward replacing.
• The $5,000 rule (rule of thumb, often used for heating and cooling). Multiply the repair cost by the age of the unit in years. If the result is above about $5,000, lean toward replacing.

Step 4: Factor in running costs. An old system that wastes energy can cost more each month than the repair saves. ENERGY STAR notes that airflow problems and neglected maintenance can cut heating and cooling efficiency by up to 15 percent and shorten equipment life. ^[2] So first check whether basic maintenance (filter, coils, servicing) solves the problem. It is the cheapest “repair” there is.

Step 5: Think about what is being compared. A cheap repair on a failing part may be the best choice if the rest of the unit is sound. Ask the technician: “If this were your house, which would you do and why?” Get a second opinion on any large bill.

Typical cost

Use the Repair or Replace Checker to see how your numbers compare. Repair and replacement costs depend heavily on the item and the place, so there is no single table. For one common decision, see how much does a new roof cost? for replacement ranges, and the roof calculator.

We do not have a sourced cost range for this yet.

Does fixing it affect property value?

“Return” is more than resale price. Where we have no reliable figure we say so instead of guessing. See how we think about value.

Repairing keeps the home working. Replacing something visible and expensive, like a roof, can matter to buyers. Zonda’s 2025 Cost vs. Value report estimates an asphalt roof replacement recoups about 68% of its cost at resale (its estimate, based on surveys and modelling). ^[3] See which home improvements add the most value for more. For hidden systems like a furnace, buyers and inspectors care more that it works and is not at the end of its life than about its brand.

Related tools

• Repair or Replace CheckerCompare age, repair cost and replacement cost against published lifespans and common rules of thumb.

Deeper technical explanation

The bathtub curve. Many things fail often early (defects), rarely in the middle of life, then more often as they wear out. That is why a repair on a 3-year-old unit is a different decision from the same repair on a 17-year-old one.

Sunk cost. What you paid for the last repair is gone either way. Compare only future costs: repair now plus likely future repairs, versus replacement.

Why the rules of thumb exist. They approximate the point where repeated repairs cost more than starting over. They ignore energy savings, safety, availability of parts and the fact that a new unit comes with a warranty, which is why a technician’s judgment matters.

Limits. The lifespan figures are from a 2007 study and the rules of thumb are unreferenced conventions. Local conditions change both.

Sources & methodology

Lifespans are from the NAHB study. Efficiency guidance is from ENERGY STAR. Rules of thumb are flagged as such. See how we work out costs.

1. Study of Life Expectancy of Home Components — National Association of Home Builders / Bank of America Home Equity (2007) Industry researchOriginal NAHB study; this link is a third-party copy. It is from 2007 and says lifespans depend on installation quality, maintenance, climate and use. Published or updated: 2007. Accessed October 4, 2026.
2. Heating and Cooling Maintenance Checklist — ENERGY STAR (U.S. EPA / DOE) Government agencyFilter checks and annual tune-ups; effect of airflow problems on efficiency. Accessed October 4, 2026.
3. Cost vs. Value Report 2025 — Zonda / Remodeling & JLC Industry researchNational averages of job cost and estimated resale value for remodeling projects. Estimates are based on surveys of real-estate professionals and cost modelling, not on measured sale prices. Scope: US national. Published or updated: 2025. Accessed October 4, 2026.