Water heater: repair or replace?

Start with the label

Every tank heater has a rating plate on the side with the brand, model, capacity and a serial number. The serial number usually encodes the manufacture date; makers publish how to read it. Knowing the age frames the decision.

A young heater with a failed part is almost always worth fixing. An older heater with a leak from the tank is not. Take a photo of the label and include it when you text.

Problems worth repairing

• Pilot will not stay lit on a gas heater: often a thermocouple or a flame sensor, a modest part.
• No hot water on an electric heater: a heating element or a thermostat, or a tripped high-limit switch.
• Leaking at a fitting or the relief valve: the leak is outside the tank, so the tank itself is fine.
• Rumbling or popping: sediment on the bottom; flushing often helps. See water heater flushing.
• Rotten egg smell from hot water: often the anode rod reacting with the water; a replacement anode can fix it.

Signs it is time to replace

• Water leaking from the tank body or pooling under it with no fitting leaks.
• Rust coming through the tank jacket or rusty hot water from every faucet.
• Repeated repairs in a short time.
• Not enough hot water for the household any more, even when working right.
• Age near or past the expected life for that heater, combined with any of the above.

A tank that leaks from the inside cannot be patched. Plan a replacement soon, before it fails completely.

What affects the price

We do not publish prices, because they depend on the house. What moves the cost: gas or electric; tank size; whether the new heater fits the old space and venting; whether the water and gas connections need updating to the current standards; seismic straps; an expansion tank where needed; hauling away the old tank; and access, such as a heater in a tight closet or an attic.

Repairs depend on the part and how hard it is to reach. Send photos and we give a free estimate for both options.

Like-for-like versus changing types

Replacing a tank with a similar tank in the same spot is handyman work we do. Switching from tank to tankless, from gas to a heat pump, or moving the heater to another location involves new gas lines, venting or electrical circuits. That is outside our scope.

Safety notes

If you smell gas, leave and call your gas utility. If the relief valve is spraying, turn off the cold water to the heater and the gas or power. Water heaters in California must be strapped for earthquakes; we check the strapping on every visit.

A quick decision guide

Young heater, part failure: repair. Leak at a fitting: repair. Rumbling: flush.

Leak from the tank or rust through the jacket: replace. Older heater with a costly repair: usually replace. When it is close, we lay out both options with photos so you can choose.

Plan ahead instead of in a rush

Water heaters tend to fail at inconvenient times. If yours is getting older, a little planning helps: know the size and fuel type, photograph the label and the space around it, and decide ahead of time if you want to stay with the same type. When it does start to fail, the decision and the order go faster, and you can avoid a cold-shower week.

Water quality

Hard water speeds sediment buildup and wears anodes. A water softener protects the heater and fixtures; see our water softener page. Flushing once a year helps any heater.

Space and access

Heaters in garages are the easiest to service and replace. Heaters in interior closets, attics or tight alcoves take longer to reach and may need a drain pan with a drain line. We note this when quoting.

Expansion tanks and pressure

Homes with a pressure regulator or a check valve on the main often need a thermal expansion tank at the heater. If your relief valve drips when the heater runs, that may be why.

Noisy pipes

Banging pipes after the heater runs are often a pressure issue, not the heater.

Recalls

Check the maker’s site with your model number for any service notices.

Hot water during the swap

How long you are without hot water depends on the job: where the tank sits, how easy it is to move, and the condition of the connections. Send photos and we will tell you what the swap involves. If parts or a new heater need ordering, we tell you how long it will take before you decide.

What to send

Photos of the rating label, the full heater with its surroundings, the top of the tank with the vent and connections, and the base. If there is a leak, a photo of where the water is coming from helps most.

Photo checklist