Unvented hot water cylinder paired with a system boiler, installed by Eco Plumbing & Heating Solutions

Unvented cylinders

Unvented hot watercylinders — installedand serviced properly.

Mains-pressure hot water cylinders installed, replaced and serviced across Rochdale, Oldham, Manchester and surrounding areas. G3 qualified, Gas Safe registered and WaterSafe approved.

Request a free quote 07582 870312

G3 qualified · Gas Safe Reg. 636807 · WaterSafe · APHC member · 12-month workmanship guarantee

Gas Safe

Reg. 636807

3rd generation

Family-run engineers

ATAG approved

Up to 18-yr warranties

24-hour quotes

Mon–Sat · 8am–6pm

£5m cover

Public liability insured

Service overview

What we do, who it's for, and when it matters.

What it is

An unvented cylinder stores hot water at mains pressure — no cold-water tank in the loft, strong showers from every outlet, and the same pressure hot as cold. We install new unvented cylinders, replace old vented tanks with unvented systems and carry out the annual servicing they legally require.

Who it's for

Homeowners upgrading from an old gravity-fed system, families adding a second bathroom or en-suite that needs proper pressure, and anyone replacing a failing cylinder that's leaking, noisy or no longer heating properly.

When you need it

If your hot water pressure is poor, your loft tank is corroding, you're removing the airing cupboard or adding bathrooms, or your existing cylinder is past its service life — a modern unvented cylinder is usually the right answer. Existing unvented cylinders also need an annual service by a G3 qualified engineer.

Why professional matters

Unvented cylinders are pressurised vessels. Fitted or serviced incorrectly, the safety controls that stop them becoming dangerous can fail. Building Regulations Part G3 requires a qualified engineer for installation and annual servicing — it's not a job for a general plumber.

The cost of leaving it

Small problems don't stay small.

Unvented cylinders are safe when installed and maintained correctly — and only then. The safety devices that protect the vessel need testing every year, and the discharge pipework needs to comply with the regulations. Cut corners here and the consequences are serious.

Unqualified installation

G3 certification is a legal requirement for installing unvented cylinders. Work carried out by an unqualified installer is non-compliant and unsafe.

Non-compliant discharge pipework

The tundish and discharge pipe from the T&P valve must be routed and sized to Building Regulations. Get it wrong and hot water can discharge into the wrong place at the wrong time.

Skipped annual service

The expansion vessel, T&P valve and pressure reducing valve all need inspection and testing every 12 months. Skipping the service invalidates warranties and lets faults build up unnoticed.

Wrong cylinder size

Undersized cylinders run out of hot water; oversized ones waste energy heating water you don't use. Sizing depends on bathroom count, family size and boiler output.

Common mistakes we see

Fitting an unvented cylinder without checking mains flow and pressure first.
Missing or under-sized discharge pipework from the T&P valve.
Ignoring the expansion vessel or pressure reducing valve at annual service.
No isolation valves or strainer on the incoming mains.
Skipping the benchmark logbook and the G3 install certificate.
Assuming an unvented cylinder is a like-for-like swap for a vented one.

Our process

A tidy, engineered process — no surprises.

Every job follows the same disciplined sequence, so you always know where we are and what's next.

Step 1
Survey & flow test
We measure incoming mains flow and pressure, check the location, plan discharge pipework routing and confirm the cylinder size that suits your hot-water demand.
Step 2
Written itemised quote
You get a written, fixed price covering the cylinder, all controls, pipework, discharge routing and commissioning — no vague ranges.
Step 3
Installation to G3
Cylinder installed to manufacturer instructions and Building Regulations Part G3, with compliant discharge pipework, isolation, filtration and expansion controls.
Step 4
Commission & handover
System filled, pressurised and commissioned, safety devices tested, benchmark logbook and G3 install certificate completed and handed to you.
Step 5
Annual service reminders
We set you up on annual service reminders so the cylinder stays compliant, safe and under warranty year after year.

What you get

Specific outcomes — not vague promises.

Mains-pressure hot water

Strong, even hot water at every outlet — no more weak showers from a loft-fed system.

No cold-water tank

Loft space freed up, no plastic tank to leak or freeze, no risk of contamination from an open vent.

Multi-bathroom capable

Sized correctly, an unvented cylinder happily supplies two showers running at once without pressure dropping.

Longer warranties

Quality unvented cylinders come with substantial manufacturer warranties when installed and serviced by a qualified engineer.

Compliant and certified

Every install carries a G3 install certificate and benchmark logbook — proper paperwork for insurance, resale and warranty claims.

One team, one guarantee

Boiler, cylinder, pipework and controls handled by one Gas Safe team — with a 12-month workmanship guarantee on top of the manufacturer warranty.

New unvented cylinder installations

Whether you're upgrading from a vented gravity-fed system or specifying a cylinder as part of a new heating install, we size to your actual hot-water demand — bathroom count, simultaneous use and boiler output — and route pipework tidily.

Cylinder sized to your household, not sold from a catalogue.
Compliant discharge pipework to Building Regulations Part G3.
Isolation, filtration, expansion vessel and pressure reducing valve fitted as standard.
Benchmark logbook and G3 install certificate completed on the day.

Cylinder replacements

Failing cylinders — corroded, leaking, noisy, or with a faulty immersion — replaced like-for-like where the existing pipework and controls are sound, or upgraded to a modern high-recovery cylinder where the wider system needs bringing forward.

Annual servicing (G3)

Unvented cylinders require an annual service by a G3 qualified engineer to remain safe and under warranty. We inspect and test the T&P valve, expansion vessel charge, pressure reducing valve and immersion, then stamp the logbook.

Cylinders for heat pumps

Air source heat pumps need a cylinder with a larger coil and lower flow temperatures than a gas boiler system. We specify heat-pump-ready unvented cylinders as part of full ASHP installs — see our heat pump page for detail.

Recent installations

Our own work — photographed on site.

Every image below is from a real Eco Plumbing & Heating Solutions job across Greater Manchester. No stock photography.

Unvented hot water cylinder installed alongside a system boiler by our Gas Safe engineers

Copper pipework and cylinder install, Greater Manchester

System boiler and cylinder pairing with tidy pipework, Rochdale

FAQs

Straight answers to the questions we hear most.

What is an unvented cylinder?+

A pressurised hot water cylinder fed directly from the mains. It stores hot water at full mains pressure, so every outlet in the house — including upstairs showers — runs at strong, even pressure without a loft tank.

Do I need mains pressure and flow to fit one?+

Yes. Unvented cylinders need a certain minimum mains flow rate and pressure to work well. We flow-test before quoting rather than assuming — if the mains isn't strong enough, we'll say so.

Do unvented cylinders need annual servicing?+

Yes. Building Regulations require an annual service by a qualified engineer to inspect and test the safety devices. Skipping it invalidates the manufacturer warranty and lets faults build up unnoticed.

Are unvented cylinders safe?+

Yes — when installed and serviced by a G3 qualified engineer and set up with compliant discharge pipework. The safety devices on a properly maintained cylinder are extremely reliable.

Can any plumber install one?+

No. Installation of unvented cylinders is covered by Building Regulations Part G3 and requires a qualified engineer. We hold the required qualification and issue a G3 install certificate with every job.

How long do unvented cylinders last?+

That depends on brand, water quality and how well they're serviced. A quality cylinder that gets its annual service will typically last well over a decade — often longer.

Can I have one with an air source heat pump?+

Yes — but you need a heat-pump-ready cylinder with a larger coil designed for lower flow temperatures. We specify these as part of our air source heat pump installs.

Is the work guaranteed?+

Yes. Every install carries a 12-month workmanship guarantee on top of the manufacturer warranty on the cylinder itself.

What areas do you cover?+

Rochdale, Oldham, Manchester, Salford, Bury, Ashton-under-Lyne, Heywood, Middleton, Shaw and surrounding Greater Manchester areas.

Ready when you are

Mains-pressure hot water, done properly.

Book a free survey and get a written, itemised quote — with flow test, sizing recommendation and no obligation to go ahead.

Get my free quote Call 07582 870312

Gas Safe Reg. 636807 · £5m public liability · Mon–Sat 8am–6pm

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