Hot Water Cylinder Repair & Replacement in Lambeth

Vetted & insured engineers Clear pricing before work starts G3-qualified for unvented cylinders No gas work — plumbing only

No hot water, lukewarm water, or a cylinder that's started to weep — our Lambeth engineers repair and replace both vented and unvented cylinders, with G3-qualified engineers routed automatically for unvented work.

Lambeth water notes: Lambeth's supply is hard, so limescale quietly shortens the life of elements and mixers from Streatham to Waterloo — worth factoring into every cylinder and shower decision. Lambeth spans grand Brixton and Herne Hill Victorians (heavily converted), large estates with communal heating and water systems, and new towers along the South Bank — three distinct plumbing worlds in one borough. Mains supply here is managed by Thames Water.

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 Lambeth job on this site involving an unvented cylinder is tagged and routed to G3-qualified engineers automatically.

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 Lambeth.

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 Lambeth itemise the cylinder, the safety kit (for unvented), and disposal, so you can compare like with like.

Cylinder costs in Lambeth

From £110 covers most Lambeth 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.

Frequently asked questions

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 Lambeth through this site is tagged g3_required and routed only to G3-qualified engineers.

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.

Do you service unvented cylinders in Lambeth?

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.

Do you cover all of Lambeth for cylinder work?

Yes, including West Norwood, Vauxhall and Clapham North — with G3-qualified engineers allocated for anything unvented.