The short version
A conventional storage tank, gas or electric, often lasts somewhere around eight to twelve years. Tankless units tend to go longer with regular service, commonly fifteen years or more. Water quality, how hard the unit works and whether anyone maintained it all shift those numbers.
Step by step
Find out how old yours is
Look at the rating plate on the side of the tank. The serial number usually encodes the manufacture date. Many brands use a letter for the month and digits for the year, though the format varies. A quick search for the brand and serial format will decode it.
Watch for these signs
- Rusty or discoloured hot water from more than one tap
- Rumbling or popping while the tank heats
- Water around the base that is not from a fitting or the relief valve
- Hot water giving out partway through a shower
- Corrosion on the top fittings or the tank shell
Upkeep that helps
- Flush some water from the drain valve once a year to clear sediment.
- Test the temperature and pressure relief valve by lifting its lever briefly.
- Have the anode rod checked every few years and replaced when it is mostly gone.
- Keep the area around a gas tank clear so it can draw air and vent properly.
Tankless units need descaling on a schedule, especially with hard water. See tankless water heater service.
A conventional storage tank, gas or electric, often lasts somewhere around eight to twelve years.
From the counter
North York notes
Toronto's water is moderately hard. Over years, those minerals settle in the bottom of tanks as sediment, which insulates the water from the burner and makes the tank work harder. Homes that never flush the tank often hear the rumbling first. Tankless units suffer too, with scale building inside the heat exchanger until the unit throws an error code or the flow drops off.
A lot of North York homeowners rent their water heater. If yours is a rental, repairs and replacement usually go through the rental company. Owned tanks can be replaced on your schedule. Read renting vs owning a water heater for the trade-offs.
When to call
Call if the tank leaks, if there is no hot water and the pilot or element seems fine, if you smell gas near a gas unit, or if the tank is well past its expected life and you want to plan rather than react. Depending on what we find, it will be water heater repair, gas water heater replacement or electric replacement. Weighing a switch? See tank vs tankless.
Any whiff of gas near the heater? Get everyone outdoors first, then phone Enbridge's emergency number from the driveway.
Questions
Should I fix an ageing water heater or replace it?
With a tank near the end of its life, a major repair often does not make sense. Smaller fixes like a thermocouple can be worth it on a younger tank.
Does flushing really extend tank life?
It helps by clearing sediment that makes the tank work harder. It will not save a tank that is already rusting through.