Hot Water Cylinder Replacement London

A hot water cylinder doesn't last forever — corrosion, a failing coil, or simply being undersized for a household that's grown since it was installed are all common reasons to replace one, whether or not the boiler itself needs attention at the same time. We replace cylinders on their own or alongside a system boiler installation.

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Sizing is the part most often got wrong: a cylinder too small for the household runs out of hot water when several people shower in succession; one too large costs more to install and takes longer to reheat than it needs to. Our survey checks occupancy, bathroom count and simultaneous demand — see our hot water cylinder sizing guide for how that works — before recommending a capacity.

We fit both vented (tank-fed) and unvented (mains-pressure) cylinders. Which one suits your property depends on your incoming mains flow rate, available space, and whether you want to keep a loft tank — the survey covers that decision honestly rather than defaulting to whichever is easiest to source.

Cylinder replacements are quoted after the free survey — vented and unvented cylinders, and different capacities, are priced differently, so we won't give a figure until we've seen the property and your hot water usage.

What you get

Free survey to size the replacement correctly for your household
Vented or unvented cylinder replacement, recommended on merit
Old cylinder removed and disposed of responsibly
Can be combined with a system boiler replacement or booked on its own
Fixed price agreed in writing before work starts
Unvented installs carried out to building regulations, with annual safety devices checked and explained

How it works

A method, not a guess

Free Survey

We check your current cylinder, household size, bathroom count, available space and incoming mains flow rate before recommending a capacity and type.

Fixed Quote

A written quote covering the new cylinder, installation, and — where relevant — removal of the old unit and any associated pipework.

Installation

Your engineer fits the new cylinder, connects it to your existing boiler and pipework, and makes good any changes agreed in the quote.

Commissioning & Handover

The cylinder is commissioned, safety devices are tested where applicable, and you're shown how the system works before we leave.

Questions

Hot Water Cylinder Replacement FAQs for London homeowners

How do I know if my cylinder needs replacing rather than repairing?

Common signs include discoloured or metallic-tasting hot water, a cylinder that's visibly corroded or leaking, inconsistent temperature, or hot water running out much faster than it used to. A survey can confirm whether a repair is realistic or replacement is the sensible option.

Vented or unvented — which do I need?

It depends on your incoming mains flow rate, available space and whether you want mains-pressure hot water at every outlet. The free survey checks these factors and recommends a type honestly, not by default.

Can I replace the cylinder without replacing the boiler?

Yes — cylinder replacement is booked as a standalone job as often as it is combined with a boiler installation. Tell us the scope when you book and the quote reflects it.

Do unvented cylinders need annual servicing?

Yes. The safety devices on an unvented cylinder are designed to be checked annually — manufacturers require it to keep the warranty valid, and it is what proves the discharge arrangements still work. It is worth combining with your annual boiler service where possible.

How long does a cylinder replacement take?

A like-for-like swap in the same location is often a single day. Moving the cylinder, upgrading pipework, or converting from vented to unvented can take longer — your quote will state the expected timescale.

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