Hot Water Cylinder Repair & Replacement — UK-Wide, Vetted & Priced Up Front
No hot water, lukewarm water, or a cylinder that's started to weep — our your area engineers repair and replace both vented and unvented cylinders, with G3-qualified engineers routed automatically for unvented work.
Vented vs unvented: what you've got matters
A vented cylinder is fed by gravity from a cold-water tank (usually in the loft) and vents to atmosphere — simple, tolerant, low-pressure. An unvented cylinder is fed directly from the mains, delivers strong pressure to every outlet, and manages expansion with a sealed vessel and safety valve set. The unvented type is legally G3-controlled: installation, and work on its safety controls, must be carried out by a G3-qualified engineer. Every your area job on this site involving an unvented cylinder is tagged and routed to G3-qualified engineers automatically.
Identify yours in seconds: a cold-water tank in the loft and a vent pipe curving over it means vented; a white or stainless pressurised unit with an expansion vessel, pressure-reducing valve and a discharge tundish means unvented. The distinction matters because unvented systems store hot water at mains pressure and are Building Regulations G3-controlled — repair and installation are restricted to qualified engineers, which is exactly who your your area job is routed to.
Common cylinder faults we repair
Failed immersion heater elements (scale-shortened life is routine in harder water), faulty cylinder thermostats causing overheat or lukewarm water, motorised valve failures leaving heating without hot water or vice versa, expansion vessel recharge or replacement on unvented systems, passing temperature/pressure relief valves discharging through the tundish, and perished coil connections. Most are same-visit repairs with carried parts in your area.
The repair list in your area runs: immersion elements and their thermostats, cylinder stats, two-port valve heads and bodies, unvented safety kit — pressure-reducing valves, expansion vessels, relief valves — and weeping connections at the coil or immersion boss. A cylinder shell that's leaking from the body itself, though, is terminal: shells aren't repairable, and we'll say so straight away rather than sell you a doomed fix. Your local water hardness affects how quickly scale builds in taps, cylinders and showers.
Repair or replace: the honest arithmetic
A cylinder under ten years old with a component fault is nearly always worth repairing. Past fifteen years, with heavy scale, repeated element failures or corrosion at the connections, replacement wins on running cost alone — a scaled coil transfers heat badly, so you pay to heat water slowly. Replacement quotes in your area itemise the cylinder, the safety kit (for unvented), and disposal, so you can compare like with like.
We price the decision, not the fear: what the repair costs now, what the cylinder's age and scale condition suggest about the next failure, and what a straight replacement costs installed. In your area's water, element and coil scaling shortens cylinder life measurably, so the crossover point comes sooner than the national average — but a sound cylinder with a £90 fault still gets the £90 fix.
Cylinder costs in your area
Component repairs — immersion elements, thermostats, valves — typically land from £110 in your area including standard parts. Unvented safety-kit work is quoted by a G3 engineer after inspection. Full replacements range widely with capacity and type: a like-for-like vented swap sits at the lower end, an unvented installation with new safety controls and discharge pipework at the upper. Every quote is itemised before work begins.
From £110 covers most your area cylinder repairs with common parts. Replacement is a bigger conversation — vented like-for-like at the affordable end, unvented systems (cylinder, G3 safety kit, discharge arrangements, commissioning) costing more but transforming shower and tap pressure. You'll get both options priced where both are viable.
| Item | Guide |
|---|---|
| Typical price band | £150–£1800 |
| Pricing basis | repairs from lower band; unvented cylinder replacement at upper band, G3 work routed accordingly |
| Typical attendance | 1–2 hours |
| Urgency profile | Standard |
Frequently asked questions
Why is water coming out of the pipe near my cylinder (the tundish)?
On an unvented cylinder, discharge through the tundish means a safety control is doing its job — commonly a flat expansion vessel or a failed pressure-reducing valve. It needs a G3-qualified engineer, and your job is routed to one automatically. Don't cap or block the discharge pipe under any circumstances.
My immersion heater keeps tripping — what's wrong?
Usually a failed element or a faulty immersion thermostat. Scale build-up shortens element life significantly in harder water areas. It's a routine same-visit repair; persistent tripping should never be 'solved' by resetting repeatedly.
Who is allowed to work on an unvented cylinder?
Installation and work on the safety controls of an unvented cylinder are Building Regulations G3-controlled and must be carried out by a qualified engineer. All unvented work booked in your area through this site is tagged g3_required and routed only to G3-qualified engineers.
How long should a hot water cylinder last?
Vented copper cylinders commonly run 15–25 years; unvented stainless units typically carry long shell warranties but rely on serviceable safety kit around them. Water hardness is the biggest variable — scale is what ages cylinders in your area. Your local water hardness affects how quickly scale builds in taps, cylinders and showers.
Why has my hot water gone lukewarm?
Likely candidates: a failed cylinder thermostat, one of two immersion elements down, a scaled coil transferring heat poorly, or a motorised valve not opening fully. Each has a distinct signature, and diagnosis is quick with the right test kit.
Is a leaking cylinder an emergency?
A weep at a connection is urgent but containable — isolate and book promptly. Water from the cylinder shell itself, or continuous hot discharge, warrants emergency attendance: isolate the cold feed to the cylinder and switch off immersion/heating first.
Do you service unvented cylinders in your area?
Yes — annual servicing (checking expansion vessel charge, relief valves, PRV operation and discharge pipework) is a G3 task, keeps warranties valid, and prevents the majority of unvented faults we get called to.
Can you replace my vented cylinder with an unvented one?
Often, yes — it removes the loft tank and gives mains-pressure hot water throughout, subject to your incoming mains flow being adequate. It's G3-notifiable installation work; we survey the mains supply first so you're not sold pressure your street can't deliver.
Do you cover all of your area for cylinder work?
Yes, including your neighbourhood, the surrounding area and nearby districts — with G3-qualified engineers allocated for anything unvented.