Specific Installation Guidance


Expansion vessels: servicing valve 

In recognition the need to carry out maintenance should take into consideration the requirement not to waste water, the installation of servicing valves on the pipework connecting an expansion vessel to an unvented water heater is permitted.

It is however recommended that these servicing valves be of a tamperproof design, such as a ‘lockshield’ valve.

For further information contact the local water undertaker.



To improve this information please give us your feedback >
Your Feedback


Uncontrolled if downloaded. This is informative, non-statutory guidance and intended for general guidance purposes only; it is subject to change.

Compliance with this information should not be relied upon as guaranteeing no enforcement action will be taken by water undertakers. Water Regs UK accepts no liability for loss, indirect or consequential loss arising from or in connection with this guidance document.