Your water heater is leaking, or the pilot will not stay lit, or you are only getting ten minutes of hot water where you used to get thirty. Someone quotes you a repair. Someone else says just replace it. Both numbers can sound reasonable on their own. Here is the actual decision rule.
The 50 Percent Rule
The rule plumbers actually use: if the repair cost is more than half of what a full replacement would cost, replace it. A $400 repair on a unit that would cost $1,200 to replace is a reasonable repair. A $700 repair on that same $1,200 replacement is not, because you are spending most of the replacement cost to keep an aging unit limping along a little longer.
What Repairs and Replacement Actually Cost
| Job | Typical Cost |
|---|---|
| Thermostat or heating element replacement | $100 – $350 |
| Mid-range repair (valve, igniter, thermocouple) | $200 – $750 |
| Full standard tank replacement, installed | $800 – $1,800 |
| Tankless or hybrid heat pump unit, installed | $2,500 – $4,500 |
| Permit (varies by city) | $50 – $500 |
If your unit needs tankless-specific work or you are considering switching from tank to tankless, our tankless vs. tank comparison covers that decision separately from repair-versus-replace.
Age Matters More Than the Symptom
A standard tank water heater typically lasts 8 to 10 years. If yours is past that mark and showing any problem, even a cheap-sounding one, replacement is usually the better call, because the next failure is not far behind and tanks that fail by leaking rather than by simply stopping can cause real water damage. If your unit is under 6 years old, a repair is usually worth doing first, since the remaining service life justifies the cost.
One symptom overrides the age question entirely: if the tank itself is leaking, not a fitting, not a valve, but the tank body, replace it. A leaking tank is not something you repair.
The California-Specific Line Item: Seismic Strapping
California requires water heaters to be seismically strapped, secured with two straps at specified heights to resist tipping during an earthquake, under state law that applies statewide, not just in obviously high-risk zones. If your existing unit is not properly strapped, or if a past installer did it wrong, a licensed installer replacing your unit will bring this up to code as part of the job. This is a small cost, usually already built into a proper installation quote, but it is worth confirming it is not skipped, since it is required, and a home inspection during a future sale will flag its absence.
A Few Signs It Is Time, Regardless of Cost Math
- Rusty or discolored hot water often means internal tank corrosion, not something a repair fixes.
- Popping or rumbling sounds usually mean sediment buildup on an aging unit; flushing helps once, but it is a sign of a tank near the end of its useful life.
- You are planning a bathroom or kitchen remodel soon. If a water heater is marginal and a remodel is already opening up walls or requiring new permits, replacing it during that project is more efficient than doing it as a separate emergency call later.
Not sure which way to go?
We will look at the unit, tell you honestly whether a repair makes sense, and handle the permit and seismic strapping correctly if replacement is the right call.
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