Is it worth repairing an old water heater?

Sometimes, if the tank is dry and the part is minor. But on an older tank, compare the repair against a replacement in writing, because the next failure may be the tank itself.

Can a plumber tell how much life a tank has left?

Not precisely. They can judge from age, rust, sediment and noise, which is why it helps to have them explain what they see rather than give a single number.

Should I replace a gas heater with the same type?

Like-for-like is the simplest swap. Changing to tankless or electric can work but often involves venting, gas line or electrical changes, so price both.

Repair or Replace a Water Heater? How to Decide Clearly

A water heater is really two things: a storage tank (or a heat exchanger, in a tankless unit) and the parts bolted onto it. The parts wear out and can be swapped: thermocouples, igniters, gas valves, elements, thermostats, relief valves, drain valves and supply connectors. The tank cannot be rebuilt. Once it leaks, it is done.

So the real question is never simply whether a repair is possible. It is whether putting a new part on this particular tank makes sense given how long the tank has been in service and what condition it is in.

Repair versus replacement at a glance

Repair usually makes sense when

The tank is dry and the failure is a single part
The heater is relatively young according to its rating plate
Venting, strapping and the gas connection are already in good shape
The size and type still suit the household

Replacement usually makes sense when

Water is coming from the tank body or the base
Several parts have failed or are failing together
Heavy sediment, rust or rumbling point to an aging tank
You want a different size, a tankless unit, or a code update anyway

Working through it

IfThe tank is leakingReplace. No repair stops a corroded tank.
IfThe tank is dry and one part has failedGet the repair price and the heater's age, then ask for a replacement price to compare.
IfThe same part keeps failingAsk the plumber why. Repeat failures can point to a gas, venting or water quality issue rather than bad luck.
IfThe heater is old and you have time to planReplacing on your schedule usually beats replacing in an emergency, when choices narrow.

Where to find the facts you need

Age: Manufacture date on the rating plate, sometimes coded in the serial number
Size: Gallon capacity and first-hour rating on the label
Fuel: Gas or electric, shown on the plate and by the vent and wiring
Condition: Rust on fittings, scorch marks at the burner, water at the base

Ask for these in writing

What failed, and is the tank itself sound?
What is the price to repair, and what is the price to replace like-for-like?
Would a replacement need venting, strapping or gas connection updates?
Is haul-away of the old heater included?
Does the job need a city permit, and who pulls it?

Common questions

Is it worth repairing an old water heater?: Sometimes, if the tank is dry and the part is minor. But on an older tank, compare the repair against a replacement in writing, because the next failure may be the tank itself.
Can a plumber tell how much life a tank has left?: Not precisely. They can judge from age, rust, sediment and noise, which is why it helps to have them explain what they see rather than give a single number.
Should I replace a gas heater with the same type?: Like-for-like is the simplest swap. Changing to tankless or electric can work but often involves venting, gas line or electrical changes, so price both.

General information for Fullerton, not a quote or professional advice. In an emergency, call 911.