CitiGas West London Gas Engineers

Gas Safe Registered Gas, Heating & Plumbing Engineers | Based in Ealing | Covering West London

Boiler and Appliance Breakdowns | Repairs | Certification | Plumbing Solutions

What can you expect from our annual boiler service and why should you get one?

  • We will ask the client whether there are any known problems or issues with the central heating system, boiler or controls. Don't be shy the more information we have the quicker we will be able to diagnose the fault and remedy the problem with a solution.
  • We will carry out a visual check on the boiler and its location and confirm whether it is up to current standards and meets the manufacturers requirements.
  • We will check the boiler, the controls and the flue for any damage or degradation.
  • We will check that the appliance is working correctly, including the consumer controls and all of the safety devices.
  • If there is a viewing screen we will check that the flame is burning correctly.
  • We will check with a multimeter that the electrical wiring is safe and correctly installed.
  • We will check for the correct clearances from combustible materials and that the access to the appliance meets manufactures requirements - we have access to all manufacturers instructions so don't worry if you have misplaced them .
  • We will examine the gas supply pipe work ensuring correct installation and clearances.
  • We will check for the correct ventilation to the room containing the appliance if ventilation is a requirement (open flue and flue-less appliances) and check that the boiler manufactures instructions are in line with the whole installation.
  • We will carry out full gas tightness test on the gas supply at the meter before removing any parts from the boiler.
  • We will remove the main burners, clean and inspect for damage unless the manufactures advises not to do so.
  • We will check the integrity of the boiler's casing seals and the combustion chamber for corrosion or damage and replace seals or gaskets if required. If parts are required we will then advise the client on costs and delivery.
  • We will clean and inspect the gas injector.
  • We will dismantle and clean the boiler pilot assembly and gas injector/spark electrodes. We will also check the condition of ignition leads and replace them if required. If parts are required we will advise the client on both costs and delivery times if applicable.
  • We will clean the heat exchanger and check for leaks or degradation.
  • We will then refit and assemble the parts and check all of the seals.
  • We will test disturbed gas joints for leaks - this is imperative. And again we will carry out a full gas tightness test on the gas supply.
  • Before running the boiler we will carry out tests on all the gas flame failure and safety devices fitted to boiler. 
  • Once the boiler is running again we will check the flame picture for the correct operation and check the inlet working gas pressure. We will also check the burner pressure or carry out a gas rate to measure how much gas the boiler is burning and if it’s within manufactures requirements. This again is imperative and if it needs adjusting we will do so if required unless the manufacturers advises otherwise.
  • We will inspect and test the flue for the correct operation by means of flue flow test and spillage test or by using a gas flue analyser. The results will be recorded and a copy of the recordings will be left with the client.
  • We will inspect the flue terminal for the correct location and the termination size and position.
  • We will also check the water content in the system or pressure in system (which ever is applicable) and bleed all of the radiators and pipe work.
  • We will also check the system for the correct heat up all around system, also looking for faults or leaks or any controls which have become damaged or are leaking or might pose a problem in the near future and advise the client if required.
  • We will then complete the appropriate paperwork for both ours and the clients records.

Manufacturers often provide instructions and guidelines on how to carry out servicing on their appliances. It is imperative to follow these so please let us know what type of appliance we will be inspecting for you. The appliance will have a data badge - this information is extremely helpful - however if you can not find one the make and model of the appliance will suffice. 

Boiler servicing takes a minimum of around an hour for a combination boiler and in some cases can take a lot longer, especially if you have a back boiler with a gas fire.  A gas fire, although appearing to be a simpler appliance, usually takes around the same amount of time because the flue and chimney system needs thorough checking. The key is to ensure your safety.


1- If your boiler is under guarantee it is very common that the warranty only applies if the boiler is serviced annually. so if you do not service your boiler annually and it breaks down you will not be able to claim the costs for repairs. Make sure that you keep the warranty.

2- You will cut your bills. Simply by making sure that your boiler is clean and efficient will have a direct impact on your household bills. If all the parts are clean and working correctly the boiler will burn fuel more efficiently than if they were not meaning that you will generate more heat from every unit of fuel burnt. 

3- You will be safer - regular servicing of gas appliances will give you peace of mind that you and your family are safe. If you are worried or simply want more information on the dangers of carbon monoxide please look at the Gas Safety Trust's website.

If you notice any of the following please organise a Gas Engineer to carry out a service:

1- The gas appliance is not working properly.

2- The appliance is burning with a lazy yellow flame rather than a crisp blue one.

3- There is evidence of black marks or stains around the gas appliance.

4- The pilot light keeps going out.

5- There is increased condensation in the room.

If you would like to book a annual boiler service we will be delighted to help so please email us at