Gas Safe Registered
No Loft Tank Overhead, Just Proper Mains Pressure At Every Tap In The House
An unvented cylinder is what gives a bigger house strong, even water pressure in every bathroom at once, without a tank in the loft rationing it out. It's also legally required to have an annual safety check by a competent, G3-qualified engineer, a rule plenty of homeowners have never actually heard of.
That check isn't optional box-ticking. An unvented cylinder stores water under mains pressure and relies on safety valves and an expansion vessel to stay that way safely, and those parts do wear. The annual check is what confirms they're still doing their job before it becomes a problem rather than after.
It's more common in the bigger, newer-built houses around Reigate and Dorking than in Horsham's older housing stock, simply because that's where the multiple-bathroom, high-demand hot water setups tend to be.
What Happens When You Call
Annual G3 safety check
Temperature and pressure relief valves, expansion vessel, and the tundish all tested properly, not glanced at.
Fault-finding if something's off
Pressure dropping, water running cold faster than it used to, or a cylinder that's noisier than it should be, diagnosed before anything's replaced.
Installation where one makes sense
Fitted alongside a new boiler or on its own, sized to actual hot water demand rather than a standard size regardless of the house.
Real Reviews For This Job
“Sam installed a new hot water cylinder in our home as well as completing some other plumbing work. Very pleased with the new hot water cylinder installation which was completed to a very high standard. I would highly recommend Sam for any plumbing or central heating work.”
Checkatrade member since March 2015, backed by their £1,000 guarantee.
Unvented Hot Water Cylinders: The Questions People Ask
What is a G3 check and why does it matter?+
It's the annual safety check the Building Regulations (Part G3) require for unvented hot water systems, carried out by a competent engineer. It confirms the safety valves protecting the cylinder from over-pressure are still working correctly.
How is unvented actually different from a standard cylinder?+
A standard vented cylinder is fed by a cold water tank in the loft, at whatever pressure gravity gives it. An unvented cylinder runs straight off mains pressure, which is why the hot water performance is usually stronger and more even.
Can an unvented cylinder be added to an existing system?+
Often, yes, provided the incoming mains pressure and flow can support it. That gets checked before anything's recommended.
How often does it actually need checking?+
Once a year, same as a boiler service, and it's often booked alongside one to save a second visit.