Replacing an Immersion Heater

Immersion heater element replacement in Leicester

Immersion heater element failure is a common fault on hot water cylinders. Lime scale and the element left on for long on a higher temperature are the main causes of failure. Select the correct type of element for your water hardness. Either use a Titanium model for hard aggressive Leicestershire water conditions, Incoloy for medium to hard water and copper for softer water conditions. Copper being the cheapest and Titanium being the most expensive. Furthermore when electricity is the only source for heating your water, an economical timer is necessary.

Also by having a cylinder thermostat to regulate the hot water temperature it will save money and prolong the life of the heating element.
Installation of a cylinder thermostat can estimate a saving of around £40 a year, which pays for it self. Installing a tank jacket and lagging the pipes will give addition savings.
A cylinder thermostat switches on and off the heat supply from the boiler/electricity to the hot-water cylinder. It works by sensing the temperature of the water inside the cylinder, switching on the water heating when the temperature falls below the thermostat setting, and switching it off once this set temperature has been reached. The recommended temperature of the cylinder stat should be between 60-65, which is high enough to kill harmful bacteria such as Legionella. Temperatures set above this range has a risk of scalding.

Replacing an immersion heater can be a simple job if you have the correct tools.

Tools required

Immersion spanner
PTFE / Joining compound
Hose Pipe

  • Isolate the power supply via the double pole spur switch, or the mains.
  • Turn off the water supply to the cylinder.
  •  Drain the cylinder by turning on the hot water taps, or the drain off cock located near the bottom of the cylinder.
  • Disconnect the electricity supply to the old immersion element. (Take a photo to recall if needed)
  • [udesign_icon_font name=”fa fa-exclamation-triangle” color=”#dd3333″] We would always recommend a qualified electrician for disconnecting and wiring of the element.

Time taken for draining of a cylinder will depend on the size of the tank. Most take 20-30min approximately, remember it is not necessary to fully drain the cylinder and you only need the water below the immersion.

  • Use the immersion spanner to undo the heating element, by applying heat can soften the compound which has become hard.
  • Install the new element ensuring to wrap PTFE tape around the thread to ensure a snug fit.
  • Reconnect the immersion to the electrical supply.
  • Re-fill the cylinder, checking thoroughly for leaks.

If no leaks are visible heat the water in the cylinder. Check periodically for leaks as the cylinder heats up.

If you’re not confident in carrying out the above call Leicester Plumbers for your plumbing and heating needs in Leicestershire.