Hot Water Cylinder Repair & Replacement in Southampton
Water dripping from the tundish on an unvented cylinder is the system telling you something — usually an expansion vessel or pressure-reducing valve fault. It's diagnosable and fixable; ignoring it isn't. We cover all of Southampton.
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 Southampton job is routed to.
Common cylinder faults we repair
The repair list in Southampton 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. Southampton sits on chalk-filtered sources and the water is decidedly hard — limescale is the defining local factor, shortening element life, furring shower heads and stiffening tap cartridges across the city.
Repair or replace: the honest arithmetic
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 Southampton'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 Southampton
From £135 covers most Southampton 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 Southampton through this site is tagged g3_required and routed only to G3-qualified engineers.
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 cover all of Southampton for cylinder work?
Yes, including Highfield, Swaythling and Portswood — with G3-qualified engineers allocated for anything unvented.
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.