Gas water heaters

If you’ve done your research on hot water heating and you’ve decided to install a gas hot water heater, you’ll need to engage with a gas fitter to install your unit. Gas hot water heaters are some of the best options on the market, a high quality unit will last for years to come. To make sure your unit runs smoothly, you need to make sure it is installed and serviced by a certified gas fitter. This is particularly important to ensure the unit remains under warranty. 

Gas hot water cylinders

Gas fitters play a very important role in maintaining gas hot water cylinders. It’s important that all maintenance and trouble-shooting is performed by a certified gasfitter and plumber to ensure the work is carried out safely and the unit remains under the warranty. 


There are several parts of the gas hot water cylinder that require a gasfitter and plumber to install. It’s very important that these parts are installed properly as they guarantee your safety and ensure the units remain under warranty. They are also responsible for ensuring the unit performs to the specifications stated on the data label. 

The temperature relief valve is responsible for ensuring that the water pressure inside the cylinder does not exceed the specified amount. This is a very complex part in the gas hot water cylinder and must be installed correctly to ensure it functions properly. 

Once installed, the gasfitter will run some tests and commission the gas hot water cylinder. This includes, but is not limited to: 

  • Open all hot water outlets in the home
  • Open the cold water isolation valve fully to the water heater. Air will be forced out of  the taps
  • Close each tap as water flows freely from it 
  • Open the gas isolation valve fully
  • Check the gas pipe work for leaks
  • Light the water heater 

Once installed, the gasfitter will give you the instruction manual that covers some basic troubleshooting; however, if you’re ever in doubt contact your local gasfitter/plumber.


Many forms of gas hot water cylinders are low maintenance. There are several parts of your hot water cylinder that require regular attention to ensure they are running smoothly. Some of these you can do yourself, others need to be checked by the professionals.

It is recommended that a service takes place once a year, once every six months and once every five years. 

The annual service should be performed by a certified plumber/gasfitter and includes:

  • Inspect and flush the temperature relief valve
  • Inspect and flush the expansion control valve (if fitted)
  • Check and adjust the inlet gas pressure
  • Check the igniter, gas control and thermocouple
  • Check and clean the pilot light and main burner
  • Visually check for any wear and tear or other potential issues

The major five year service is recommended to prolong the lifespan of your hot water cylinder, it includes all the items above plus a few additional checks:

  • Replace the temperature relief valve
  • Inspect and replace (if required) anode

It is also recommended that you do a minor side monthly maintenance, this does not require a gasfitter, the instructions of your cylinder will give you detailed instructions on how to do this. 

Continuous flow gas water heater

As with the gas hot water cylinders, these also require a plumber/gasfitter to install and service the unit. 


Once the gasfitter installed the unit, they will need to commission it to ensure it performs to the required specifications. For a continuous flow gas hot water heater, this can include:

  • Open all the hot water outlets in the house 
  • Open the cold water isolation valve fully at the inlet to the water, air will be forced out of the taps
  • Close each tap as water flows freely from it
  • Check the pipework for leaks
  • Open the gas isolation valve fully
  • Check the gas pipework for any leaks 
  • Plug in the water heater at the power outlet and switch on the electrical supply
  • Turn on the controller
  • Open a hot water outlet
  • Check the flow from each connected hot water tap
  • Check and adjust the the preset outlet temperature
  • Check and adjust the outlet compensation temperature adjustment 

To complete the installation, it is necessary to check the gas supply pressure at the inlet to the water heater, the minimum test point pressure and the maximum point pressure.

Once completed, the gasfitter will show you how to operate your unit. 


In terms of general maintenance, there are some things you can do without the input of a gasfitter. This includes cleaning the external jacket of the unit with warm mild soapy water. 

A minor maintenance every six months is recommended, this can also be performed by you. IT mainly includes inspecting the unit for any plant growth and insect infestations. 

A major service is recommended every five years, this will need to be performed by a certified plumber/gas fitter and includes: 

  • Checking and adjusting the gas pressure
  • Check the operation of and clean the burner
  • Check and clean the line strainer
  • Visually check the unit for any potential issues
  • Inspect all connections

If you can smell gas at any point, contact your gas fitter first for advice and a service. 

Our gas fitters are certified to install and maintain your gas water heater, get in touch with us today for a consultation to see how we can help you.