Hot Water Cylinder Repair & Replacement in Southwark
A hot water cylinder fails in stages: longer reheat times, temperature drift, discharge from the relief pipework, then leaks from the shell. Caught early in Southwark, most of those stages are a repair, not a replacement.
Vented vs unvented: what you've got matters
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 Southwark 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 Southwark.
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 Southwark itemise the cylinder, the safety kit (for unvented), and disposal, so you can compare like with like.
Cylinder costs in Southwark
From £135 covers most Southwark 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 Southwark 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 Southwark. Southwark shares the capital's hard water, and scale shows up early in the borough's hard-worked conversions and new-build blocks alike — descaling and inhibitor fits are routine here.
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.