Its your gas valve, grey button 240v valve, easy to change on them boilers , you need a gas engineer as you have SEALS involved and need to check burner pressure. gas valves are around £98-00 to £138-00 depending on where you go. You may get them cheaper but the prices change all over the Uk
HELL i have even bought them for £20-00 down southampton.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local