Hot Water Cylinder Repair & Replacement in London

Immersion heater tripping the electrics? Cylinder taking twice as long to heat? These are specific, diagnosable faults with known causes, and our London engineers carry the common parts: elements, thermostats, immersion heaters and valve kits.

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

Common cylinder faults we repair

The repair list in London 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. London's supply is hard — Thames Water draws heavily from chalk aquifers and the Thames itself, so limescale builds fast on heating elements, shower heads and tap internals.

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

Cylinder costs in London

Component repairs — immersion elements, thermostats, valves — typically land from £110 in London 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.