Should I repair or replace my water heater? What it costs
Repair a tank that is under about 6 to 8 years old when one part has failed. Replace it when the repair would cost more than 50% of a new unit, or when the tank itself leaks. Tank replacements commonly run $600 to $3,100 installed, and tankless installs $1,400 to $5,600 (2026 national ranges).
The library
What this library covers
Water Heater Facts is a learning library for homeowners. Each page answers one question, cites the manufacturer, the government agency or the code that backs it up, and says plainly when a job belongs to a licensed plumber. We are an information site run by Strive LeadGen LLC. We are not a plumbing company, and we can connect you with an independent licensed plumber if you want one.
The library has five working parts:
- Troubleshooting: symptom pages for no hot water, leaks, noises, smells and pilot problems, each split into safe homeowner checks and pro-only work.
- Error codes: plain-English tables for Rinnai, Navien and Rheem tankless codes, paraphrased from the makers' service documents.
- Repair or replace: the age and cost math, plus how long each type lasts.
- Costs and buying guides: dated price ranges from named sources, sizing, and tank vs tankless.
- Age decoder: read the build date off your serial number.
How to use it
- Find the age first. Most repair or replace decisions turn on age. A tank past 10 years is a different decision from a 4-year-old tank with a bad part[1].
- Match your symptom. Start at the troubleshooting page for what you see or hear. Each one lists what you can safely check and where to stop.
- Check the cost math. If a repair quote is more than half the price of a new unit, Rheem's guidance is to replace[1].
One more thing to know before you shop: the 30% federal tax credit (25C) does not apply to water heaters placed in service after December 31, 2025[3]. Many older articles still say it does.
The three most common problems
- No hot water from a gas tank: usually gas supply, the pilot or ignition, or a safety lockout.
- Leaking from the bottom: could be the relief valve, the drain valve, condensation, or a failed tank. Only the last one forces a replacement.
- Relief valve dripping: often thermal expansion, which a plumber fixes with an expansion tank, not a plug.
If you smell gas, skip this site: leave the house and call your gas utility or 911 from outside.
When to call a pro
- Any gas smell, scorch marks, or a relief valve releasing hot water or steam.
- Water coming from the tank body itself.
- Any repair behind a sealed panel, on a gas valve, or on wiring.
- A replacement: many cities and counties require a permit and inspection for it, and some let only a registered plumber pull that permit.