Covent Garden, London•Mon–Fri 8am–5pm•24/7 On-Line•chelsea_hpco@hotmail.com Covent Garden • 24/7 On-Line Gas Safe Reg. 952303 HomeAboutServicesBoiler InstallationBoiler RepairsBoiler ServicingGas EngineerLandlord CP12Smart ControlsRadiatorsPlumbingDrainagePowerflushingCentral HeatingHot Water CylindersBathroomsView all Services → AreasElthamMottinghamNew ElthamKidbrookeBlackheathSidcupWellingBexleyheathChislehurstBromleyWoolwichLeeGreenwichLewishamLondonKentView all Areas → Our WorkContact07460 067161 Request Estimate HomeServicesCentral Heating Gas Safe Reg. 952303 · South East London & Kent Border # Central HeatingFor London Homes —Designed, Fitted, Balanced. Whether it's a full first-time install, a system upgrade from an old vented cylinder to a modern unvented one, additional radiators for an extension, or a controls overhaul that finally makes the upstairs actually warm — we design, fit and commission complete central heating systems in London properties. Request Free Estimate 07460 067161 System designed, not just fitted · Gas Safe Reg. 952303 · G3 Unvented qualified · 12-month workmanship guarantee Gas Safe Reg. 952303 Owner-operated Ian Fisher Workmanship guarantee 12 Months Fixed-price options No VAT Owner-engineer Ian Fisher Overview ## Central heating done as a system, not a pile of parts. A central heating system is a designed hydraulic circuit — boiler output, pipe sizes, radiator emitter capacity, pump duty, expansion volume, controls topology and hot-water storage all have to be sized against each other. Get any one wrong and you get the classic complaints: cold radiators upstairs, tepid showers when the heating is on, boiler locking out on high return temperatures, huge gas bills for a lukewarm house. Chelsea Plumbing & Heating Co. designs and installs full central heating systems across South East London and the Kent border. That includes new-build first-fixes, complete system replacements in older properties, extension add-ons, cylinder upgrades (vented to unvented, G3-qualified), controls overhauls, and remedial work on systems that were never properly commissioned by whoever fitted them originally. This service is for homeowners planning a boiler replacement who also want the rest of the system brought up to modern standard, extension projects that need heating added to new rooms, landlords whose properties are underperforming on EPC ratings, and anyone whose heating 'just doesn't work properly' and wants the actual cause diagnosed rather than another patch job. The single biggest driver of comfort and running cost is not the boiler brand — it's the system design. Correct pipe sizing, correctly sized radiators for each room's heat loss, a proper commissioning balance, and modern controls with weather compensation typically save 25–40% on running costs versus the same boiler installed onto an untouched older circuit. What happens if you leave it ## Why bolt-on heating jobs cost you twice. The most common failure mode we're called to is a new boiler fitted onto an old, sludged circuit with no filter and no flush. Within six months the new heat exchanger is blocked with black magnetite from the old radiators, the manufacturer refuses the warranty (no Benchmark, no filter), and the homeowner is looking at another £2,000+ appliance three years early. The second is extension radiators bolted onto a system that wasn't sized for them. The new rads work, but the far-end original ones now don't — because the pump can't drive flow through a longer, wider circuit. What was meant to add heat has removed it from the rooms that used to be warm. The third is 'more powerful boiler = warmer house' logic. Wrong. If the pipework, radiators or controls can't deliver the output the boiler can produce, you've just paid for a bigger appliance to short-cycle and wear out faster. Common costly mistakes - ×Adding radiators without recalculating pump duty or resizing pipework — new rads work, old ones go cold. - ×Fitting a new boiler onto a sludged circuit with no flush and no magnetic filter — voids warranty, kills the new heat exchanger. - ×Choosing radiator size on aesthetics alone — a designer radiator with 40% less output than the room needs will never heat that room. - ×Leaving TRVs sitting on manufacturer default — no zoning, no efficiency, and one thermostat controlling the whole house. - ×DIY unvented cylinder work — legally requires a G3-qualified engineer. Non-compliant installs are uninsurable. - ×Using microbore pipework decisions from 30 years ago as the template for a modern high-efficiency system. Our process ## A methodical system,not a rushed callout. - 01 Survey & heat-loss On-site survey, room-by-room heat-loss calculation, existing system audit, pipework and controls assessment. - 02 System design Boiler sized, radiators specified per room, cylinder sized (if applicable), controls topology chosen, fixed written proposal issued. - 03 Install Old components stripped, pipework upgraded where needed, new boiler, radiators and controls fitted. - 04 Flush & balance Powerflush of retained pipework, magnetic filter fitted, inhibitor dosed, every radiator balanced individually. - 05 Commission & guarantee Full system commissioning, controls programmed, Benchmark completed, 12-month workmanship guarantee issued in writing. Why it pays off ## Concrete outcomes,not vague promises. ### Comfort in every room Radiators sized to room heat-loss and balanced individually — no more 'the back bedroom never warms up' in January. ### 25–40% lower running costs Weather compensation, correctly-sized boiler, low return temperatures and zoned controls deliver measurably lower bills. ### Warrantied end-to-end Boiler warranty (7–10 years), radiator warranties (typically 10 years on quality brands), plus our 12-month workmanship cover. ### G3 Unvented qualified Fully qualified for unvented cylinder work — legally required, and the difference between mains-pressure hot water and a poor shower. ### One engineer, one plan Ian designs it, Ian fits it, Ian commissions it. No design-vs-install communication gaps that cost you money later. ### Coordinated with other trades For extension and renovation projects we coordinate with builders, electricians and kitchen/bathroom fitters — first-fix and second-fix scheduled properly. Recent work ## Photographs fromactual jobs. Real installations, repairs and diagnostics carried out by Ian across South East London and the Kent border. No stock photography. Technical detail ## Central heating scope we cover. Central heating is a broad category — here's the specific work we do most often across London properties, from Victorian terraces to modern flats to landlord portfolios. ### Full system replacements Boiler + radiators + controls + pipework flush + magnetic filter on properties where the existing system is at end of life. Sized against a fresh heat-loss survey, not just copied from what was there before. ### Vented-to-unvented conversions Removing loft header tanks and vented cylinders, installing a G3-compliant unvented cylinder for mains-pressure hot water throughout — including all statutory discharge pipework and tundish arrangements. ### Extension add-ons New radiator circuits sized to the extension's heat loss, pump duty re-checked, controls extended, and existing rooms re-balanced so nothing loses output. ### Radiator upgrades & swaps Old single-panel radiators swapped for double-panel or vertical designer units with correct output. TRVs fitted, chrome or brass valve pairs supplied, existing pipework re-routed where needed. ### Controls & zoning Smart thermostats (Nest, Hive, Tado, Honeywell Evohome), weather-compensation sensors, room-by-room TRVs, and multi-zone valve arrangements for properties with clearly separated heating demands. ### Hot-water cylinders Direct and indirect unvented cylinders, sizing based on peak simultaneous demand (bath + shower + basin), G3-qualified installation and annual servicing. ### System flushing & inhibitor dosing Full powerflush of existing circuits before a new boiler is added — the non-negotiable step that keeps manufacturer warranties intact. ### Pipework upgrades Microbore to 15/22mm upgrades where flow is inadequate, chrome pipework for exposed installs, and buried pipework re-routing during extension or refurbishment work. FAQ ## Answers beforeyou commit. Not covered here? Call Ian directly on 07460 067161. How much does a full central heating install cost in London?A full new system with boiler, radiators, controls, pipework and flush typically runs from £5,500 upwards on a 2–3 bedroom property, depending on scope. Every project is priced in writing after a survey — no hidden extras. How long does a full system install take?A straightforward 2–3 bedroom full system replacement is typically 3–5 working days. Extension add-ons and cylinder conversions can vary from 2 to 6 days depending on pipework routing. Do you work on unvented cylinders?Yes — Ian is G3-qualified (the legally-required qualification for unvented hot-water cylinder installation, commissioning and servicing). Every unvented install includes the correct discharge pipework and tundish arrangement. Can I keep some of my existing radiators?Often yes — if they're the right size for the room. We assess each radiator on the survey and only recommend a swap if the existing unit is undersized, damaged or a poor match for a rebalanced system. Do you fit smart thermostats?Yes — Google Nest, Hive, Tado and Honeywell Evohome are all fitted and paired to the boiler as part of a new install or as a controls upgrade to an existing system. What's the difference between a system and a combi boiler for central heating?Combi does heating and instantaneous hot water in one appliance — best for smaller homes. System boiler pairs with an unvented cylinder to deliver mains-pressure hot water to multiple outlets at once — best for 2+ bathroom properties. Do I need a powerflush?Any time an old system is retained and a new boiler is fitted, yes. Manufacturer warranties are conditional on system cleanliness, and a magnetic filter alone is not enough to catch decades of magnetite already sitting in the pipework. Can you handle the electrical work for the controls?Yes — control wiring for programmers, motorised valves, cylinder stats and room stats is part of the install. Any consumer-unit work is coordinated with a qualified electrician. Will you help me claim any grant funding?Where a job qualifies for grant funding (varies by scheme and eligibility) we can help you understand the paperwork requirements. We do not directly administer grant schemes. Which areas do you cover for central heating?South East London and the Kent border — Eltham, Mottingham, New Eltham, Kidbrooke, Blackheath, Sidcup, Welling, Bexleyheath, Chislehurst, Bromley, Woolwich, Lee, Greenwich and Lewisham. RelatedBoiler InstallationPowerflushingRadiatorsBoiler ServicingHomepageContact Book with confidence ## 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. Request Free Estimate 07460 067161 Gas Safe registered plumbing and heating specialists based in Covent Garden — boiler installation, servicing, repair and full central heating across South East London and the Kent border. Gas Safe Reg. 952303 · ACS · G3 Unvented · NVQ Level 3 ### Services - Boiler Installation - Boiler Repairs - Boiler Servicing - Gas Engineer - Landlord CP12 - Smart Controls - Radiators - Plumbing - Drainage - Powerflushing - Central Heating - Hot Water Cylinders - Bathrooms ### Areas - Eltham - Mottingham - New Eltham - Kidbrooke - Blackheath - Sidcup - Welling - Bexleyheath - Chislehurst - Bromley - Woolwich - Lee - Greenwich - Lewisham ### Contact - 71–75 Shelton Street,Covent Garden,London WC2H 9JQ - 07460 067161 - chelsea_hpco@hotmail.com - Mon–Fri 8am–5pmOut-of-hours cover available24/7 On-Line — line available 24/7 © 2026 Chelsea Plumbing & Heating Co. All rights reserved. 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