Accommodation of expansion
The water fittings regulations/byelaws permit the accommodation of thermal expansion from unvented water heaters (with the exception of instantaneous water heaters with a capacity less than 15 litres) within the secondary hot water system.
This is however only permitted if:
For further information contact the local water undertaker.
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.