Leaking hot water heater? Tips to fix a leaking hot water tank.

23 Oct

leaking water heater

IMPORTANT: If your hot water heater is leaking a substantial amount, i.e. more than a bucket of water in 24 hours, we strongly recommend you call us for advice and emergency assistance as it could be an indication of a serious problem.  If not, read on. 

“Help! My hot water heater is leaking. What should I do?”

This is one of the most common emergency calls for assistance we receive from customers every day.

The outside location of most gas, electric and solar hot water systems mean that most people don’t realise their hot water heater is leaking until they start running out of hot water prematurely. Worse, it may not be until they completely run out of hot water that they take measures to locate the problem and, only then, discover the leak.

Of course, a leaking indoor hot water heater can also go unnoticed and usually causes bigger issues caused by internal water damage.  This is why we strongly recommend that your hot water system should be serviced every few years as this should identify and resolve problems even before they arise.

Helpful readingWhy you should regularly service your hot water system »

Unfortunately, in time, all hot water heaters will eventually fail and need replacing.  For storage water heaters this is usually evident by water leaking from the storage tank continuously. You can often temporarily maintain the supply of hot water by turning off the cold water supply valve on the inlet to the water heater in between usage periods.

For substantial leaks from electric hot water systems you can completely turn off the water supply to the heater along with the power switch in your electrical meter board. If your gas hot water heater is leaking, turn off the gas valve beside the heater to isolate the gas supply.

Identifying the source of the HWS leak

There are several reasons why your hot water heater may be leaking. This most common are listed below. 


The tank has corroded causing cracks or fractures to appear that enable water to leak out. Unfortunately this usually means a replacement hot water system is required.  Sometimes these cracks can be “mended”.  Your water heater type and location determines the best repair option. Speak with one of our hot water specialists for advice about what to do.

If you have a solar or electric hot water system and it is leaking from the top or bottom of the tank it’s important you turn off the electricity before inspecting the problem. Water and electricity don’t mix and can be extremely dangerous for the inexperienced. Typically your hot water system will run off it’s own fuse so you should be able to just turn off the HWS and continue using other appliances as normal.

Helpful reading: Hot water replacement costs

Pressure relief valve

The pressure relief valve or pressure temperature valve at the bottom of the tank may need replacing. Please note it is normal for these to leak a little water from time to time but not on a steady basis.  If the pressure valve is leaking try lifting the lever several times. This opens and closes the valve and can help clear any blockages. If the water keeps running, contact us for assistance as the valve probably needs replacement. This isn’t an expensive repair.

Helfpul reading: Don’t risk voiding your hot water system warranty.

Turning off the water supply

Turning off the water supply is the same for all solar, electric and gas hot water systems.

Close to the HWS there should be a small tap or lever on a pipe feeding into the bottom of the system. Turn this off fully turning the tap anti-clockwise. This only turns off the water to the hot water system, not the rest of the taps in the home so you can continue using them as normal.

If you can’t turn the tap or lever then it may have corroded and seized up over time. If this is the case you will need to isolate and shut off the mains tap which will be near your water meter.  Please note this will turn off the water supply not only to your hot water heater but the entire house.  It’s a good idea to fill a few buckets and bottles with water so you’ve got fresh water on standby until you resolve the leak.

Turn off the gas supply

If your gas hot water heater is leaking then you’ll also need to turn off the gas.  There should be another pipe running into the system, also with a tap or lever attached. Turn this off too.

Helpful reading: How to relight your Rheem Stellar or Rheem 5 Star gas hot water heater.

Unable to fix your leaking hot water system?

If the tips above don’t fix your leaking hot water heater then it may be time to call in the experts.

Your hot water system is an expensive appliance and really should only be serviced and repaired by an authorised, licensed hot water plumber (like us). Did you know that most manufacturers won’t cover the terms of your warranty it’s not installed or repaired by a licensed hot water technician or qualified plumber. It’s not worth the risk!

Usually we can give you a realistic quote over the phone as to how much it is likely to cost to repair a leaking hot water heater, including replacement parts.  Call us for a quote on 1800 266 999 or complete our hot water quote form and we’ll get back to you shortly.

Emergency leaking hot water repairs Sydney.

For fast leaking water heater repair and replacement service call the expert hot water specialists at Cheapa Hot Water Sydney on 1800 266 999. We are available 7 days and offer a fast, emergency after hours repairs. Our trucks are on the road right now stocked with replacement parts for all hot water heater makes and models. We service all Sydney suburbs and the NSW Central Coast.

Call 1800 266 999 Email us Request a quote

The information on this website is of a general nature only. We do not make an warranties about the completeness, accuracy or reliability of this information or whether it is relevant to your specific hot water problem(s). For professional hot water repair advice specific to you, contact our Sydney hot water specialists direct on 1800 266 999.
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