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How Long Does a Water Heater Last?


An average water heater tank lasts around 12 years.

But yours could be an outlier in either direction. It might only last 7 years if you don’t stick to a regular maintenance schedule and it may serve your household for 16 years or more if you take meticulous care (and score a little good luck).

How does it deteriorate if it’s just sitting there, holding water?

An anode rod protects the interior lining of your water tank by attracting tiny corrosive particles.

The rod itself corrodes as the particles build up, and eventually it can’t keep up. The particles begin settling at the bottom of the water tank, where the lining of the tank breaks down.

Once this corrosion starts, there’s no way to save the tank. It’s on its last legs.

Full Maintenance includes flushing the sediment, every 3-4 years, extending the lifespan of your water heater tank even when it enters this final stage of life.

Tankless water heaters live longer.

Tankless water heaters can last 20 years or longer, but require annual maintenance visits.

Tankless heaters don’t run continually and don’t suffer the same corrosive effects of storing heated water (because they don’t store any water).

The water passing through your tankless heater still breaks down the appliance, so maintenance is still required every  year, and eventually it will need replacing. But that’s a long time down the road.

How do I know the age of my tank?

The serial number on your water heater reveals its age.

The serial number consists of a letter and series of numbers.

The letter stands for the month:

  • A for January.
  • B for February.
  • C for March.
  • D for April.

…and so on.

The next two numbers indicate the year it was manufactured.

So a serial number of L04 or L4 would be found on a water heater built in December 2004.

How can you tell when your water heater is going downhill?

These signs indicate your water heater is on the way out. If you notice any, it’s time to start shopping for a replacement.

  • As sediment builds up on the bottom of your tank, the material begins to make banging or deep rumbling noises when in operation. If you notice these sounds, the sediment has built up too thickly to be flushed and it will break down in the immediate future.
  • Discoloured hot water is an indication of rust in the water heater. Usually this shows up as red or a dirty sort of yellow colour. If the discolouration only happens when hot water runs, it’s in the water tank. If it happens when cold water runs, it may be in the pipes along the way (and an easy fix).
  • A noticeable drop in hot water temperatures is a sign of the approaching end. This usually happens quickly, over the course of a few days, so it’s very noticeable.
  • Water leaking from the bottom of the tank is a clear indicator of a dying water heater. Corrosion inside eventually leads to cracks on the outside, and there is no repairing at that point.

The good thing about replacing your aging water heater is you end up with something more efficient. Technology is constantly improving and modern water heaters cost significantly less every month to keep you showering comfortably.

Have a look at our free online water heater calculator and see how much your new water heater can save your family when you get it installed.

Start saving for your purchase early so you’re ready to make the upgrade when your existing tank kicks the bucket.

If you want to talk about your options with a professional, call your local Clarity by ClimateCare retailer today!