How long does an electric water heater last

Getting hot water into your home (or business) is done using either electricity or gas. If you’re using electricity to heat your water, then you’ll probably have a hot water heater either somewhere in your house. Most often it’s in a closet – some people still refer to as the cylinder cupboard – or it’s in a space under the stairs. (Who doesn’t have memories of putting wet clothes or towels to dry in the cylinder cupboard?)

If you’re currently using an electric hot water cylinder, you may be wondering how long it should last. It’s a good idea to look into the timing and cost of replacing it before it actually stops working.

How long should an electric hot water system last?

On average, an electric hot water heater should last around 10 to 15 years. Most manufacturers’ warranties are for 10 years.

So if you’ve recently purchased a home with a water tank that’s close to 10 years old, you will probably want to budget in replacing it sometime soon. You may still get a number of years out of it, depending on how much it’s has been used (how many people lived in the house, how often they used hot water) and how well it’s been looked after.

At Cylinder Direct we offer a few rules of thumb about the age of a hot water cylinder.

More than 20 years old

It’s time to replace your hot water cylinder. By now, your system is out of warranty (most are valid for 10 years) and it’s getting too expensive to replace any of the valves. By the time you factor in the cost of new replacement valves, possibly the thermostat or other parts, plus labour, you’re getting close to the cost of a brand-new cylinder.

Between 15-20 years old

Whether you need to replace a cylinder that is around the 15-year mark, or get a few more years out of it, depends on a few factors. Give us a call and we can talk it through with you. We’ll take into consideration any problems you’re having with your hot water cylinder, your supply of hot water, your household usage, and the financial pros and cons of repair vs replacement.

10-15 years old

With a hot water heater that is between 10 and 15 years old, it’s usually cost-effective to repair the system. Any noises, leaks, temperature or flow issues can often be remedied by replacing valves, the thermostat or other parts attached to the cylinder.

Less than 10 years old

If your hot water heater is less than 10 years old, and you suspect there is damage or a faulty valve or part somewhere, we’ll always look to repair rather than replace the system entirely. The only time we’ll consider removing a hot water cylinder that is this “new” is if there is actually damage to the cylinder itself (extremely rare) or if you’re looking at swapping over to a continuous flow hot water system.

How do I know how old our hot water cylinder is?

The easiest way to determine the age of your hot water cylinder is by looking at the information on the large white sticker on it. Depending on the brand, the manufacture date might be clearly written out. Otherwise, you can determine the date it was made by looking at the serial number. The last four digits will usually be the month and year of manufacture.

Another useful tool is the online Rheem serial number search function. Just go to and enter the serial number from the sticker and you’ll find out the age of your cylinder. (Obviously, this only works for Rheem models.) And to find the serial number on a Rinnai model, have a look at .

Troubleshooting – why has my hot water cylinder stopped working?

The first hint that there might be something wrong with your electric hot water cylinder is you’ll notice the water isn’t as hot as it should be, or you’re getting sporadic hot water (sometimes it’s hot, sometimes it’s not). Perhaps you’ve run out of hot water altogether.

Alternatively, you might hear unusual noises, banging or hissing from your water cylinder. Or you might notice water leaking from the tank.

All of these are signs that something isn’t working as it should. But it may not necessarily mean it’s time to replace your hot water cylinder. At Cylinder Direct, we’re experts at diagnosing problems with water heating systems of all types, and (depending on the age of your cylinder) we’ll always try to repair before replacing if that’s the most economical thing to do.

Often, when a hot water cylinder isn’t working as it should, it’s not actually the cylinder – it’s the parts associated with it. Your hot water system is actually made up of the cylinder (and inner and an outer cylinder), valves, fittings and a thermostat.

Please note that there should not be water “leaking” from your cylinder, but there will always be a small amount of water released from the cylinder from a valve connected to the cylinder. This should be a slow drip (of approximately one to two litres a day), not a leak or constant drain of any more than that.

So we’ll first determine what’s wrong and where the issue lies. If there’s something amiss with the valves or the thermostat, we’ll see if we can repair or replace those. But if the cylinder is damaged, it will need to be replaced.

At this time, you may want to consider switching from electric to gas, or moving to a continuous flow hot water system. Give us a call and we can discuss the options with you.

How do you ensure a hot water cylinder lasts as long as possible?

Like any household appliance, it takes proper looking after and maintenance. Many people don’t even think about maintenance work on their hot water cylinder – it’s out of sight, out of mind.

But there are ways we can look after it to help it last past that 10-year mark. We can have a look over all of the parts and valves to check they’re all working correctly – before anything goes wrong so you don’t suddenly lose hot water. We can test that the thermostat is functioning properly and is set at the right temperature for your household. And we can check if the insulation around it is adequate.

Prevention of problems is always better (and cheaper) than fixing them, so give us a call if you think it’s time to have your cylinder checked.

Have a read here of our article “How do I know if my hot water cylinder needs replacing?”

As always, if you have any questions at all about your water heating, give us a call for a free, no-obligation chat.