Unvented Hot Water Cylinders and Systems


unvented cylinder2Unvented Stored Hot Water is the “holy grail” of hot water unvented cylinderdelivery: no noisy pumps, no waiting for a bath to fill – all the hot water you want at exactly the temperature you want.

PowerFlushUK installs, commissions and services unvented systems.

If you’re having problems with your unvented hot water system, have a look at our simple diagnostic chart.


What is unvented or mains pressure hot water?

The easiest way to explain “unvented hot water” is that it is the opposite of the typical British vented system: there are no tanks or pipe work in the roof and you have the benefit of full and equal mains pressure on both hot and cold.

The Unvented Hot Water System was invented in 1861 by an Englishman named Thomas Hawksley and adopted throughout the world with the exception of the United Kingdom until legislation in the form of the 1985 Building Regulations and the 1986 Model Water Bylaws was introduced. The legislation is very prescriptive about how and who may undertake work on unvented systems.

If you are a property owner, Landlord or Local Authority, PowerFlushUK installs, commissions and services unvented cylinders.
We will travel anywhere in the UK for contract servicing.What are the building regulations?
In brief: the Building Regulations relate to proper fitting of the minimum of 9 accessories which ensure the safe operating environment of the cylinder and the proper fitting and siting of the D1 & D2 discharge pipes.

If you have, or want to have an unvented system the Benchmark Certificate provided with the appliance is the proof that will satisfy the Building Control Officer or insurance companies that the appliance has been installed and commissioned safely.