What an unvented hot-water cylinder does

An unvented hot-water cylinder stores hot water under mains pressure, rather than relying on a header tank in the loft. This typically means stronger water pressure at your taps and shower.

Why they need specialist installation

Because unvented cylinders operate under pressure, they include safety devices such as a pressure relief valve, expansion vessel and temperature controls to manage that pressure safely. Installation and servicing legally requires G3 qualification, which David holds.

Common signs something needs attention

1. Water dripping from the pressure relief valve discharge pipe
2. A noticeable drop in hot-water pressure
3. Unusual noises from the cylinder or nearby pipework
4. No hot water despite the boiler or immersion appearing to work