The Value of TradeoffsRead the guide →

Decision calculator

Repair the water heater or replace it?

Compare three paths over the same horizon: repair now, replace with a standard tank, or replace with a heat pump water heater.

Reviewed Oct. 1, 2026Model v6.1.5How our models work
Tank water heater installed in a utility room
Use quotes and utility estimates from your home.

Installation constraints, fuel type, hot-water demand, incentives, venting, electrical work, and local rates can materially change the result.

Step 1

Quick comparison

Start with the repair, repaired life, comparison horizon, and the two installed replacement quotes.

Start here

Values shown are editable example defaults. Replace them with your quotes and utility estimates.

Not sure what to enter? See how example defaults work →

Jump to current result ↓
Live resultUpdates as the assumptions change

—

—

Repair path——
Standard tank now——
Heat pump now——
What changes the answer?Repair life and operating cost.

—

How stable is this result?

—

Stress test: the base case, a weaker repair case, and a stronger efficiency case.

See the math

—

Test the decision

Move the two assumptions most likely to change the repair path.

$900
2 years

Step 2 · optional

Replacement assumptions

Fine-tune fallback choice, operating costs, future repairs, and verified incentives.

Show details

Do not assume an incentive applies until you verify eligibility. Compare equivalent scope, including required electrical, plumbing, venting, condensate, permits, and disposal.

Why these defaults? Source notes and assumptions · How defaults work

Current system & fallback

Standard tank

Heat pump water heater

Defaults are editableReplace example assumptions with your quotes, rates, and expected life.
Close calls stay closeScenario checks show when reasonable assumption changes can flip the result.
Math is visibleOpen “See the math” to audit the calculation structure.

When this calculator may not be enough

Fuel switching, electrical-panel work, gas venting, space temperature, noise, condensate drainage, hot-water recovery, local codes, warranties, and emergency replacement timing can outweigh a small modeled difference.

Read the full guide →

Try a worked example

Example: repair versus two replacement paths

Try a $900 repair expected to buy two years, then compare an all-in standard tank quote with a heat-pump water-heater quote over ten years.

Edge case to stress-test

Test a home that needs electrical upgrades or has high installation costs. Upfront work can overwhelm projected energy savings.

Related decisions

Explore this decision clusterHow our models workHVAC repair vs. replaceHeat pump vs. gas furnaceAppliance repair vs. replace

Same horizon

All three paths are compared over the same period.

Delayed replacement

The repair path includes a later replacement if the repaired unit does not last through the horizon.

No incentive guessing

Tax credits and rebates are user-entered only after you verify eligibility.

Understand the comparison

These estimates are undiscounted: they do not model inflation, the time value of money, or every future failure. Monthly equivalents divide modeled cost across the period; they are not loan payments. Read the scope and exclusions for each model.

Resolve safety concerns with a qualified professional before comparing cost. Confirm quote scope, eligibility for incentives, and expected service life.