A decision framework based on hundreds of real service calls.
Updated April 2026
• Unit is over 10 years old AND needs any repair over $200
• Rusty water from the hot tap (tank corroding internally)
• Puddle at the base (tank body leaking — not repairable)
• Third repair call this year
• Repair cost exceeds 30% of replacement cost
| Repair | Installed cost | Worth it under 8 yrs? |
|---|---|---|
| Thermostat replacement | $75 – $250 | Yes |
| Anode rod replacement | $150 – $300 | Yes |
| T&P relief valve | $100 – $250 | Yes |
| Water heater flush | $80 – $200 | Yes |
| Type | Installed cost |
|---|---|
| Tank water heater | $800 – $2,500 |
| Tankless water heater | $1,500 – $4,000 |
A $250 repair on a 10-year-old unit today, plus another $250 repair within 2 years, plus eventual replacement ($1,650 average) = $2,150 over 5 years. Replacing now costs $1,650 once with a new warranty. The math usually favors replacement once the unit passes 70% of its expected lifespan.
Rusty water from hot tap only. Rumbling or popping sounds. Puddle at the base. Water takes longer to heat. Unit is over 10 years old. Three or more of these = the unit is done.
Based on national trade data and contractor experience. Updated April 2026. All ranges are for planning purposes only — not a quote or guarantee. Actual costs vary by region, scope, access, materials, and contractor.