A Guide To Hot Water Heater Maintenance

Fatal accidents can occur if gas-fired water heaters are not regularly checked for issues, such as potential gas leaks.
  • Posted by HeatElectric Team
  • 9 min read (1216 words)
  • Last updated 02 Dec, 2022


Heaters with tanks have safety features that allow excess temperature and pressure to escape, but if these safety features are not properly checked, explosions can happen.

A typical water heater lasts between 8 and 12 years, but only if it is properly maintained. Before completing any maintenance tasks on your hot water heater, make sure you shut off the power.

  • If you have an electric hot water heater, switch off the circuit breaker for the water heater in your home’s service panel.
  • If you have a gas hot water heater, turn the pilot knob to the off position.


It is recommended that you have your water heater flushed out at least once every year, as well as inspect your heater’s rods, coils and other vital parts. If you notice any of the following signs, you should take action as soon as possible.

  • Leaks
    Obviously, you’ll know that you need to carry out maintenance if you see a leak or a puddle surrounding your heater. However, not all the signs of a leak are so evident. Try to check for leaks around your water heater at least once a month – look for drips, damp flooring, or even a musty smell surrounding the heater.
  • Low Pressure
    Low water pressure could be due to a build-up of minerals or other types of sediment, or could be due to a kink in a pipe.
  • Clicking Noises
    Your water heater will make some random noises that aren’t cause for concern. However if you start to hear constant clanging, clicking or even popping sounds, this could be a sign of a more serious issue, such as clogs in the system. This can run up your water bill and can lead to an increased risk of burns.
  • Discoloured Water
    If your water looks rusty and is reddish-brown in colour, your system needs maintenance. This could mean the pipes have started to rust, or there could be a problem with your water heater.


Test the Pressure Relief Valve

The temperature and pressure relief valve is a critical safety feature of your water heater. It senses dangerous pressure build-up of excessively high temperatures inside the water heater tank, and automatically opens to relieve the pressure. Without an operational temperature and pressure relief valve, your water heater is at risk of explosion.

The valve is usually located either at the top of the heater tank or in the side wall, and has a discharge tube that extends down towards the base of the tank. To test the valve, first place a bucket under the end of the discharge tube. Lift the lever of the valve up to open it manually. Hot water will be released through the tube and into the bucket. Be careful, as this water will be very hot.

If the valve doesn’t open and release water, or if it leaks after the test, we recommend you get this replaced.

Inspect The Anode Rod

The anode rod is a vital component of a standard hot water heater, as it helps to prevent tank corrosion and rusting. It is a steel wire with aluminium, aluminium/zinc alloy or magnesium wrapped around it that runs down the centre of the tank. The anode rod’s purpose is to wear itself down to maintain the tank. As it erodes, it releases electrons into the water heater tank which helps to slow or prevent corrosion. Deterioration is the most common anode rod issue in a hot water heater. If the steel wire of the rod’s core is exposed, we recommend that you replace it.

Flush The Tank

If you don’t flush your water heater tank annually, sediment can accumulate in the bottom. When a layer of sediment covers the bottom of the water heater, it can reduce the efficiency of the heater and lead to damage.

We recommend turning the water heater off the night before you flush the tank, to allow the water to cool. Not only will this reduce the risk of burns, but you could also use the water for another purpose – perhaps to water the garden. When the heater’s power is off and the water is cold, attach a garden hose to the drain valve and extend the other end to an area where the tank can safely drain. Open a nearby hot water tap to avoid creating a vacuum in the system, and open the drain valve. Let the tank drain for around 10-20 minutes, then fill a bucket with water. Let the bucket sit for around one minute completely undisturbed, then check to see if there’s any sediment in the bottom. If the water is cloudy or there is sediment in the bottom of the bucket, you need to keep draining the tank. Check again after 10 minutes, repeating until the water is clear and free of sediment.

Once the water is clear and there aren’t any signs of sediment, close the drain valve and remove the garden hose. Keep the pressure relief or hot water tap open to help bleed air from the line. Open the water supply valve and let the tank fill up. You’ll know when it’s full as water will be flowing at full pressure through the open tap.

Adjust Water Temperature

The thermostat on your water heater is an important safety feature. It ensures the water in your heater doesn’t get too hot. Check the thermostat to ensure it’s set to the correct temperature. If you do adjust the water temperature, wait at least three hours before testing the temperature.


Hot water heater maintenance can be expensive and time consuming. Here at Heat Electric, we believe that Sunamp heat batteries are the future – they require little or no maintenance, so no need for costly annual inspections or servicing by engineers, paired with a lifespan of over 50 years of average use.

They deliver mains pressure hot water on demand with superb efficiency. Packed with modern electric water heating technology, Sunamp heat batteries are ultra compact and can be charged using an off-peak energy tariff, or divert energy from solar PV, heat pumps or other renewable sources. They are perfect for those conscious about reducing carbon emissions, reducing or eliminating gas usage and controlling energy bills.

Heat Electric are specialists in ultra-modern and efficient electric heating. We’re proud to be a Which? Trusted Trader for our high standards of customer service, value and quality, and our NAPIT accredited installers work to a no mess, no fuss policy when fitting your stylish new heating system.

Contact or call us today to book your free home survey on 01244 371445.

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