Check the supply
Mains pressure and flow decide whether unvented storage is an option.
Heating · Hot water
Hot water that keeps up with the household.
From a copper cylinder in the airing cupboard fed by a tank in the loft to an unvented cylinder running at mains pressure, we repair, replace and upgrade hot water storage, and fit the safety equipment unvented cylinders depend on.
- Gas Safe registered
- MCS heat pumps
- F-Gas certified
What’s included
The work, done properly.
- Vented cylinders replaced like for like or upsized
- Unvented cylinders installed by G3-qualified engineers
- Annual unvented checks: safety valves, expansion vessel and discharge pipe
- Immersion heater and cylinder thermostat replacement
- Motorised valve and controls repairs
- Heat pump cylinders with larger heating coils
Signs you need this
- Hot water runs out halfway through the second shower
- Weak showers on the top floor, fed from a loft tank
- Water running through the tundish on an unvented cylinder
- A leaking or corroded cylinder in the airing cupboard
- Hot water only works on the immersion, not from the boiler
A vented cylinder is fed by a cold water tank in the loft, so its pressure comes from the height of that tank, which is why top-floor showers are often weak. An unvented cylinder runs straight from the mains at much higher pressure, giving strong showers throughout the house and freeing the loft, but it needs good mains flow and proper safety controls.
Because an unvented cylinder holds hot water under pressure, it has to be installed by someone with the G3 qualification, and its safety valves should be checked every year. Water appearing in the tundish, the small open funnel on the discharge pipe, is the system telling you a valve or the expansion vessel needs attention. Do not ignore it.
How it works
Size the cylinder
Bathrooms, people and how they use water, not just the size of the old one.
Install
Cylinder, valves and discharge pipework fitted to the regulations.
Commission
Safety devices tested, controls set and paperwork completed.
- Gas Safe registeredEvery gas job is done by an engineer on the Gas Safe Register.
- MCS-certified heat pumpsRequired for Boiler Upgrade Scheme grants.
- F-Gas certifiedAir conditioning and refrigerant work done to the regulations.
- Fully insuredPublic liability cover, with certificates for freeholders and agents.
Book hot water cylinders
Tell us what’s going on.
Send the address and a few details. We’ll confirm timing and next steps, and you’ll get a written price before any work starts.
Prefer to talk? 020 7946 0182
Questions
Hot water cylinders, answered.
Should I switch from vented to unvented?
If your mains flow and pressure are good enough, it usually means better showers and a clear loft. We measure the supply before recommending it.
Does an unvented cylinder need servicing?
Yes. The safety valves, expansion vessel and discharge pipe should be checked every year, and many manufacturer warranties expect it.
Do I still need a cylinder with a combi?
No. A combi heats water as you use it, so the cylinder and loft tanks usually come out. In a home with two or more busy bathrooms, a system boiler with a cylinder is often the better choice.
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