Bathrooms In London —
Plumbing, Heating & Hot
Water, Done As One Job.
Full bathroom installations and refurbs where the plumbing and heating side is scoped, coordinated and installed by a Gas Safe engineer who understands the whole system — not by a builder who calls a different plumber every day. Mains-pressure showers, unvented cylinders, heated towel rails, underfloor circuits.
The plumbing side of a bathroom project, done properly.
A new bathroom lives or dies on the plumbing and heating decisions taken at first-fix — before a single tile is laid. Shower pressure, water temperature stability, waste run gradients, radiator or heated towel rail sizing, and hot-water storage capacity all have to be right on the day the walls close. Fix them afterwards and you're pulling tiles.
Chelsea Plumbing & Heating Co. handles the full plumbing, heating and hot-water side of bathroom installations and refurbishments across London. That includes stripping the existing bathroom, first-fixing new pipework and waste runs, sizing the hot-water supply for the new outlets, fitting radiators or heated towel rails, coordinating with the builder and tiler through the shell stage, and second-fixing the sanitary ware, taps, showers and radiators once the room is ready.
This service is for homeowners planning a full bathroom refurb who want the plumbing and heating scoped as one job, extension projects that need a new en-suite added to an existing hot-water system, and landlords upgrading tired bathrooms in let properties.
The building work (walls, tiling, flooring, decoration) is coordinated with trusted local builders — we quote and manage the plumbing and heating scope, and either work alongside your builder or bring one in for you. Gas Safe registered (952303) and G3-qualified for unvented cylinder work, which matters the moment you want mains-pressure hot water to a decent shower.
What goes wrong in bathroom refurbs handled by non-heating trades.
The classic failure: a beautiful new shower fitted to an under-sized combi boiler that can't deliver more than 8 litres per minute — half of what the shower head expects — so the customer has a lukewarm dribble every morning for the next ten years. Diagnosed and prevented at first-fix, uncorrectable afterwards without ripping walls open.
The second: a heated towel rail that looks the part but is 40% under the room's heat-loss requirement. The bathroom feels cold in January, the towels never dry, and the only real fix is to add a radiator that wasn't planned for.
The third: waste runs installed at the wrong gradient (or worse, upstream of an air admittance valve that can't handle a bath and a shower simultaneously). By the time you notice the slow drain and the smell, the tiling is done.
And the persistent one: a compliant unvented cylinder installation being carried out — or worse, not being certified — by anyone without G3 qualification. Void insurance, illegal install, and a mandatory rip-out on discovery.
- ×Fitting a mains-pressure shower to a combi that can't deliver the flow rate — the shower will never work properly.
- ×Choosing a heated towel rail on style alone with no heat-output calculation for the room.
- ×Waste runs graded flat or reversed — slow drainage and eventual smell.
- ×Non-G3 engineer touching an unvented cylinder — illegal and uninsurable.
- ×Isolation valves not fitted at first-fix — meaning any future tap or shower repair requires a full system shut-off.
- ×Underfloor heating manifold installed without a proper zone valve or blending valve — floor gets too hot, warranty voided.
A methodical system,
not a rushed callout.
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01Survey & specExisting pressures, flows, hot-water source and heating capacity all measured against the new bathroom's demand.
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02Quote & scheduleWritten fixed-price scope for plumbing and heating, timeline agreed and coordinated with builder/tiler.
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03Strip & first-fixExisting bathroom stripped, new pipework, waste runs and cylinder/pipework upgrades installed before walls close.
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04Second-fixOnce tiling and units are in, sanitary ware, taps, showers, radiators and towel rails fitted and connected.
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05Test & handoverEvery outlet tested for flow, temperature and drainage. Site left clean, 12-month workmanship guarantee issued.
Concrete outcomes,
not vague promises.
Mains-pressure hot water
Where the property allows, unvented cylinder upgrades deliver full-flow mains-pressure hot water to showers, baths and basins simultaneously.
Radiators & towel rails sized properly
Heat-output calculation for the bathroom — no more cold rooms with 'nice-looking' but undersized towel rails.
Coordinated with your builder
First-fix timing coordinated so pipework is in before walls close, and second-fix scheduled once tiling is complete.
G3 unvented qualified
Legally qualified for unvented cylinder installation — critical for any bathroom expecting mains-pressure showers.
Isolation valves throughout
Every fixture fitted with its own isolation valve — future repairs don't require a whole-property shut-down.
Warrantied end-to-end
12-month workmanship guarantee on the plumbing and heating side, plus manufacturer warranties on radiators, showers and cylinders.
Bathroom plumbing scope we cover.
Full-scope plumbing and heating on bathroom installations and refurbs across London — every element below designed, fitted and commissioned by a Gas Safe registered, G3-qualified engineer.
Hot-water sizing
Peak simultaneous demand assessed (shower + bath + basin), and hot-water source specified against it — combi boiler with adequate flow, unvented cylinder, or system upgrade.
Unvented cylinders (G3)
Installation, commissioning, tundish and discharge pipework, expansion vessel sizing, and PRV settings — all to G3 Building Regulations.
Mains-pressure showers
Mixer, thermostatic mixer and digital showers fitted. Flow-rate matched to available pressure so the shower actually performs as it should.
Baths, basins and WCs
Freestanding and built-in baths, wall-hung and pedestal basins, back-to-wall and concealed-cistern WCs — plumbed for the correct fill rate, flush volume and waste gradient.
Heated towel rails & radiators
Heat-output calculation for the bathroom, correct valve pair (chrome, brass or angled where needed), and correct pipework routing behind tiles.
Underfloor heating (wet)
Wet underfloor circuits with proper manifold, zone valve, actuator and blending valve arrangement — plumbed in to the existing heating system correctly.
Waste and drainage
New waste runs graded correctly, traps sized to fixture type, air admittance valves specified only where compliant with local building regulations.
First-fix and second-fix coordination
First-fix pipework and waste in before walls close. Second-fix (taps, showers, radiators, sanitary ware) once tiling is complete and units are in.
En-suite additions
Adding a new en-suite to an existing property — hot-water and heating capacity assessed, pipework routed through the building fabric with builder coordination.
How much does a bathroom refurbishment cost in London?
Plumbing and heating scope on a full bathroom refurb typically ranges from £2,500 to £6,500 depending on unvented upgrades, underfloor heating and shower complexity. Every project is quoted in writing after survey. Building, tiling and decoration are separate and can be coordinated.
How long does a bathroom install take?
A full strip-and-refit typically runs 7–14 working days including first-fix, tiling and second-fix, coordinated with the builder. The plumbing and heating scope alone is typically 3–5 days split across first- and second-fix.
Do you do the building work as well?
We handle the plumbing and heating scope directly. Building, tiling and decoration are coordinated with trusted local trades — either your existing builder or one we can bring in. One point of contact for the whole project on request.
Will my combi boiler run a decent shower?
Depends on its output rating (kW) and your incoming mains pressure. We measure both at survey and tell you honestly whether the shower you want will work — before you buy it.
Do I need an unvented cylinder for a good shower?
If you want mains-pressure hot water to more than one outlet at a time (shower + basin, or two showers in different bathrooms), yes — an unvented cylinder is the usual answer. G3-qualified installation is legally required.
Can you fit underfloor heating in the bathroom?
Yes — wet underfloor heating circuits fitted and plumbed into the main heating system with correct manifold and blending valve arrangement.
Can you handle en-suite additions?
Yes — adding a new en-suite to an existing property is a common project. We assess whether the existing hot-water system can handle the additional demand and quote any upgrades needed alongside the new bathroom scope.
What guarantee do I get?
12-month workmanship guarantee on all plumbing and heating labour, plus manufacturer warranties on radiators, cylinders, showers and sanitary ware.
Do you handle landlord bathroom refurbs?
Yes — landlord and letting-agent bathroom refurb work is a common part of our workload, coordinated around tenancy change-overs.
Which areas do you cover for bathroom work?
Greater London and the surrounding Home Counties — Kent, Surrey, Essex, Hertfordshire, Buckinghamshire, Berkshire, Bedfordshire, Middlesex and West Sussex.
Fixed price. Gas Safe.
12-month guarantee.
Free estimates from Ian directly — no call centre, no subcontractors, no surprise bills. One point of contact from first call to twelve-month follow-up.