Boiler & Cylinder Combined Replacement London

When a boiler and its cylinder are roughly the same age, they often reach the point of needing attention together — and doing both in a single visit is usually more practical and less disruptive than two separate jobs booked months apart. This service covers a system or regular boiler replacement and a cylinder replacement as one coordinated project.

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The advantage of doing both together isn't just convenience: sizing the boiler and cylinder as a matched pair, based on the same survey of your bathrooms and hot water demand, avoids the mismatch that can happen when a new boiler is fitted to an old, undersized cylinder or vice versa.

This is quoted as a single job with a single fixed price — not two invoices — and commissioned together so both the boiler's Benchmark checklist and the cylinder's safety checks are completed in the same visit.

This is quoted as a single combined job after the free survey — boiler output and cylinder capacity are priced together once we know both are being replaced, which is often more cost-effective than booking the two separately.

What you get

One free survey covering both the boiler and the cylinder
Boiler and cylinder sized as a matched pair, not assessed separately
One written, fixed price for the whole job
Old boiler and old cylinder both removed and disposed of responsibly
Fully Gas Safe registered engineers, Benchmark commissioning completed
Suits households replacing an ageing system boiler set-up in one visit rather than two

How it works

A method, not a guess

Free Survey

We assess your existing boiler, cylinder, radiator circuit, bathroom count and hot water demand together, as one system.

Fixed Quote

A single written quote covering the new boiler, the new cylinder, installation and old unit removal — sized to match each other.

Installation

Your engineer fits the new boiler and cylinder in the same visit, minimising disruption compared with two separate jobs.

Commissioning & Handover

Both the boiler's Benchmark checklist and the cylinder's commissioning and safety checks are completed before we leave, and you're shown how the combined system works.

Questions

Boiler & Cylinder Combined Replacement FAQs for London homeowners

Is it cheaper to replace the boiler and cylinder together?

It's often more cost-effective than two separate call-outs, since labour, access and commissioning are shared across one visit — but every job is quoted on its own scope, so the free survey is what confirms the actual figure.

Do I have to replace both at the same time?

No — this service is for households who want to, typically because both units are ageing together. If only one needs replacing, our standalone new boiler installation or hot water cylinder replacement services cover that.

Will I be without hot water and heating for longer than a normal boiler swap?

Usually one to two days, similar to a system boiler conversion — your quote will state the expected timescale based on what the survey finds.

Can this include switching from vented to an unvented cylinder?

Yes — if you're replacing the cylinder anyway, moving to an unvented cylinder is worth discussing in the survey, provided your incoming mains flow rate supports it.

How do you decide the right boiler and cylinder sizes together?

The same survey factors apply as our individual services — bathroom count, simultaneous hot water demand and radiator count — but assessed as one system so the cylinder capacity actually matches the boiler's output rather than being sized separately.

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