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London plumber fitting a vented hot water cylinder in an airing cupboard
From £895 fitted — same-day quote

Vented Cylinder Replacement London

Traditional gravity-fed hot water cylinder replacement across all 32 London boroughs. Copper, stainless and twin-coil tanks from £895 fitted. Loft header tank checks, new immersion fitted as standard, Benchmark commissioning logbook on every job.

Like-for-like swaps completed in a single day. Direct or indirect, 90L to 300L. No G3 ticket needed for vented work — but our engineers hold one anyway.

0207 046 1363WhatsApp 07456 975436Book online
£5M Public liability
BS 1566 Grade 3 cylinders
24/7 Emergency cover
25-yr Tank warranty (stainless)
60 min Zone 1–2 response
Quick answer

A vented hot water cylinder is a traditional, low-pressure tank fed by gravity from a loft header tank. Replacement in London runs from £895 fitted (120L copper) to £1,495 fitted (210L twin-coil stainless). Most like-for-like swaps complete in a single day. No G3 ticket needed — vented systems are not sealed pressure vessels.

What is a vented hot water cylinder?

A vented cylinder is the traditional UK hot water store: a copper or stainless tank fed by gravity from a cold water cistern (the loft "header" tank). The cylinder itself is not sealed — it has an open vent pipe rising back up and discharging over the F&E tank, so any pressure or expansion vents harmlessly into the cistern rather than building up inside the cylinder. That open arrangement is the entire engineering trick of a vented system: no expansion vessel, no pressure relief valve, no discharge pipe to outside.

The pressure at every hot tap is determined by the height of the loft tank above the outlet — roughly 0.1 bar per metre of head. A typical London terrace with a tank 4–6 m above the ground floor delivers 0.4–0.6 bar at the bath. That's why traditional vented showers feel weaker than mains-pressure unvented ones, and why power-shower pumps are common on gravity-fed properties.

Vented cylinders are split into direct (heated only by an immersion element — common in all-electric flats) and indirect (heated by a coil fed from a gas or oil boiler primary circuit, with the immersion as backup). Across London the dominant brands are Telford Tempest, Gledhill Stainless Lite, Range Tribune and unbranded BS 1566 grade 3 copper cylinders. Stainless tanks carry 25-year warranties; copper cylinders typically 1–5 years.

Vented vs unvented — which is right for your home?

The single most-asked cylinder question in London. The short answer: stick with vented if your existing gravity system performs acceptably and your budget is tight; move to unvented if you want mains-pressure showers, want to free up the loft, or are doing a wider refurb.

FeatureVentedUnvented
Pressure sourceGravity from loft header tank (~0.1 bar/metre of head)Sealed at mains cold pressure (typically 3.0–3.5 bar)
Loft tank requiredYes — cold water storage cistern (F&E tank)No — fed directly from cold mains
Shower flow rateOften needs a pump for power-shower performanceStrong mains-pressure flow to every outlet
Install complexitySimpler — no G3 ticket required, no discharge pipeG3 qualified engineer mandatory under Building Regs Part G3
Fitted cost (180L equivalent)From £1,095–£1,295From £1,745–£1,895
Annual servicingNot legally required (sensible every 2–3 years)Annual G3 service mandatory to preserve warranty
Best forPeriod properties, low-mains-pressure areas, budget swapsMulti-bathroom homes, top-floor flats, power-shower setups

For the full conversion specification and pricing, see our unvented cylinders London page. Conversions start at £2,495 fitted.

Sizing guide — what capacity do you need?

Vented systems are slower to recover than unvented (lower flow turnover), so when borderline we recommend sizing up rather than down. The Hot Water Association rule is 35–45 litres per occupant plus 60 litres per bathroom.

PropertyRecommended capacityNotes
1-bed flat / studio (1 person)90–117LSmallest vented copper option. Suitable where bath usage is occasional. Header tank often a 18L combined.
2-bed flat (2 people)120–144LMost common London 2-bed swap. Allows full bath plus shower without re-heat wait.
3-bed terrace (3–4 people)162–180LSweet spot for traditional gravity-fed terraces. Pairs with a 230L F&E header in the loft.
4-bed semi (4–5 people)210LTwin-coil 210L recommended if pairing with a future solar thermal or heat-pump retrofit.
5-bed family home / 2 bath245–300LLarger gravity-fed homes — consider conversion to unvented for mains-pressure flow if header tank height is limited.
Indirect vented copper cylinder with header tank in a London loft

Brand comparison — what we fit in London

Five vented cylinder ranges cover 95% of London installs. The right pick depends on whether you want a budget like-for-like copper swap or a long-warranty stainless upgrade.

Telford Tempest (vented stainless)

Fitted from £1,295

Premium UK-made stainless steel vented cylinder, 25-year tank warranty, factory-foamed insulation. The benchmark for new vented installs in London where the customer wants to keep the gravity system but upgrade from old copper.

Gledhill Stainless Lite Direct/Indirect (vented)

Fitted from £1,195

Stainless steel duplex tank, factory-foamed, 144L–210L typical range. Well-supplied in Greater London, twin immersion boss as standard. Strong recovery rate.

Range Tribune HE (vented variant)

Fitted from £995

BS 1566 grade 3 copper or stainless options. Reliable mid-range choice. Cheaper to swap like-for-like into an existing copper-cylinder cupboard.

Albion Mainsflow (vented copper)

Fitted from £895

Traditional copper cylinder built to BS 699 / BS 1566. Most common when a customer needs a direct-replacement copper unit to fit an existing immersion-only setup.

Telford Mainsflow (vented, twin-coil)

Fitted from £1,495

Twin-coil version pre-piped for solar thermal or heat-pump compatibility. Worth specifying now even if the second heat source is years away — saves a future re-pipe.

Vented cylinder replacement cost London — 2026 prices

Every price below is supply & fit, fully inclusive — new cylinder, drain-down of the existing system, like-for-like primary & secondary pipework, new immersion element and thermostat, refill, vent, Benchmark commissioning logbook, disposal of the old cylinder, and 12 months ERL workmanship warranty. No call-out fee on quoted work.

JobWhat's includedTypical cost
120L vented copper cylinder — fittedSupply & fit indirect copper cylinder, drain-down, like-for-like primary & secondary connections, new immersion, lagging jacket, system refill and vent.£895
144L vented copper cylinder — fittedSupply & fit BS 1566 grade 3 copper cylinder for 2–3 bed terrace, primary/secondary swap, factory-foam jacket, new immersion element and stat.£995
162L vented copper cylinder — fittedSupply & fit larger indirect copper cylinder, full pipework alterations, header tank check, draining and recommissioning.£1,095
180L vented stainless / Telford Tempest — fittedPremium stainless tank with 25-year warranty, like-for-like header-fed install, balanced cold feed, full system flush included.£1,295
210L vented twin-coil (solar-ready) — fittedTwin-coil cylinder for solar thermal / second heat source, two indirect circuits piped in copper, dual thermostat wiring.£1,495
Direct vented cylinder (electric only)Supply & fit direct cylinder where no boiler primary exists — typical for off-grid or all-electric flats, twin immersion fitted.from £825
Header / F&E tank replacementReplace cold water storage cistern in loft, new ball valve, isolation, insulation jacket, lid and vermin mesh per Water Regs.£325–£465
Immersion heater + thermostat (during swap)New 3 kW Incoloy immersion element, dual thermostat, drain to immersion boss, refill, vent, electrical safety check.£165 add-on
Vented cylinder repair / leak fixSoldered seam repair (where viable), cold feed re-pipe, primary blanking plate, immersion gasket swap, recommission.from £185
Full vented-to-unvented conversionRemove vented cylinder + loft tank, install unvented cylinder, G3 safety group, new discharge pipework, building control notification.from £2,495

* Prices include VAT and Water Regs notification. Full price list on our pricing page.

Want a fixed quote for your specific cylinder?

Call 0207 046 1363

Installation process — 5 steps, one day

Every vented cylinder swap follows the same five-stage process. Indicative total time on site is 3.5–5 hours for an accessible airing cupboard; up to 7 hours for restricted Victorian access or pipework alterations.

1

Survey & quote

30 min on site

Engineer measures the existing cylinder cupboard, checks pipework layout, header tank capacity, primary flow & return positions, and electrical immersion supply. Written fixed-price quote issued before any drain-down begins.

2

Isolate & drain

30–60 min

Boiler isolated, cold feed valve closed at the F&E tank, primary loop drained to the lowest point (usually rad valve), cylinder drained via the immersion boss or fitted drain cock. Old immersion stat and thermostat disconnected.

3

Remove & install

60–90 min

Old cylinder withdrawn, scaffold cradle used in restricted London cupboards, new cylinder placed on level base, primary flow/return tapped in copper or push-fit, cold feed and open vent re-instated, new immersion fitted with PTFE-sealed boss.

4

Refill, vent & commission

45–75 min

System slowly refilled from the F&E header, air bled at every high point, primary circulating pump run to clear air locks, cylinder thermostat set to 60°C, immersion thermostat to 65°C, run-up to temperature witnessed.

5

Handover & paperwork

15 min

Benchmark commissioning logbook completed, electrical safety on the immersion checked against BS 7671 18th Edition, jacket lagging fitted, customer demonstrated on isolation, cold feed and emergency drain-off. Certificate emailed within 24 hours.

ERL engineer commissioning a vented hot water cylinder in a London property

Compliance & Benchmark commissioning

Even though Building Regulations Part G3 does not apply to vented cylinders, every install is still notifiable under the Water Supply (Water Fittings) Regulations 1999 and must meet a stack of British Standards. The Benchmark logbook ships with every new cylinder and stays with the property — it is what proves the install was commissioned correctly when the warranty is called on.

BS 1566

Copper hot water storage cylinders

The product standard every vented copper cylinder sold in the UK is built to. Grade 3 is the modern minimum — wall thickness, dome strength and connection sizes are dictated by the standard. Avoid uncertified imports.

BS 699

Specification for copper direct cylinders for domestic purposes

Covers the direct (electric-only) variants — wall thickness, immersion boss positioning, working pressure. Many older flats with no boiler primary still run a BS 699 direct copper cylinder.

BS EN 12828

Heating systems in buildings — design for water-based heating

Governs the primary circuit between the boiler and the cylinder coil — pump sizing, expansion provision on the heating side, control strategy and safety devices.

Building Regs Part L

Conservation of fuel and power

Replacement cylinders must meet the Part L declared heat-loss rate. Modern factory-foamed cylinders comfortably pass; older spray-foamed or jacketed units do not. We log the heat-loss figure in the handover pack.

Water Regs 1999

Water Supply (Water Fittings) Regulations 1999

Even vented systems are notifiable when the system arrangement changes (e.g. new immersion circuit, change of fluid category). We notify the relevant water undertaker as part of every install.

Benchmark

HHIC Benchmark commissioning scheme

Every new vented cylinder install gets a completed Benchmark commissioning entry — system fill date, inhibitor dose, thermostat set-points, signed by the engineer. Required by every UK manufacturer to keep the warranty alive.

Completed Benchmark commissioning logbook entry for a vented hot water cylinder

Real London vented cylinder jobs

Five recent jobs from the last twelve months, anonymised. Diagnostic, work done, time on site, final figure.

1960s terrace, Walthamstow — 144L copper cylinder swap

Original 1968 indirect copper cylinder, scale-clogged primary coil giving 20-minute reheat times. Like-for-like swap to a 144L BS 1566 grade 3 copper cylinder with factory-foamed jacket. New immersion fitted as backup, F&E tank ball valve replaced while drained. Time on site: 4 hours. Final invoice: £1,065 inc. VAT.

Victorian conversion flat, Stoke Newington — leaking weld

Tenant reported staining on the airing-cupboard floor. Diagnosed pinhole weld leak on a 1990s copper cylinder — uneconomic to repair given the tank age. Replaced with a 120L vented copper cylinder, kept the existing F&E header (sound). Time on site: 3.5 hours. Cost: £945 inc. VAT.

Edwardian semi, Crouch End — Telford Tempest upgrade

Homeowner wanted to keep the gravity-fed system (no mains pressure upgrade) but step up to a 180L Telford Tempest stainless cylinder for the family bath schedule. Boiler primaries re-piped in 22 mm copper to clear an old elbow restriction. Time on site: 5 hours. Cost: £1,365 inc. VAT.

Mansion-block flat, Maida Vale — immersion-only swap

All-electric flat, no boiler, 1980s direct copper cylinder with a failed immersion element and pin-hole on the side seam. Replaced with a 117L direct vented cylinder, twin 3 kW Incoloy immersion elements, new dual thermostat, 1-hour Economy 7 wiring tidied. Time on site: 3 hours. Cost: £915 inc. VAT.

1930s semi, Ealing — twin-coil for solar-ready upgrade

Homeowner planning a solar-thermal install in 12 months. Specified a 210L twin-coil vented cylinder now to avoid a second drain-down later. Primary boiler coil piped, solar coil blanked off with isolation valves ready. Time on site: 5.5 hours. Cost: £1,545 inc. VAT.

Vented cylinder leaking, scaling or scheduled for upgrade?

Same-day diagnostic and fixed-price quote. Like-for-like swaps usually done in a single day. Water Regs notification, Benchmark logbook, new immersion and 12-month workmanship guarantee — all in the quoted price.

Call 0207 046 1363WhatsApp 07456 975436Book online

Frequently asked questions

What is a vented hot water cylinder?
A vented cylinder is a traditional, low-pressure hot water tank fed by gravity from a cold water storage cistern (the loft header tank). Unlike an unvented cylinder, it is not sealed — it has an open vent pipe rising above the loft tank to relieve any pressure or expansion safely into the cistern. Pressure at the taps is determined purely by the height of the loft tank above each outlet, typically 0.1 bar per metre of head. They are the simplest, oldest and cheapest hot water storage configuration in the UK and still very common in pre-2000 London housing stock.
How much does a vented cylinder replacement cost in London?
Like-for-like vented cylinder replacements in London run from £895 fitted (120L copper) to £1,495 fitted (210L twin-coil stainless). The 144L–180L range covers most 2–3 bed properties at £995–£1,295 fitted, including supply, drain-down, immersion element, factory lagging jacket, refill, vent, commissioning and disposal of the old unit. Add £325–£465 if the loft header tank is also being replaced. A full vented-to-unvented conversion costs from £2,495 and adds a G3 safety group, expansion vessel and a routed discharge pipe.
Is a vented cylinder cheaper than unvented?
Yes — typically £400–£800 cheaper fitted for an equivalent size, because vented installs are simpler (no G3 ticket required, no expansion vessel, no discharge pipe, no temperature-and-pressure relief valve). The trade-off is performance — gravity-fed vented systems deliver lower flow rates and weaker showers unless boosted by a pump. If you already have a working header tank in the loft and your shower performance is acceptable, replacing like-for-like vented is the more economical route.
Do I need a G3 engineer for vented cylinder replacement?
No — G3 certification is only legally required for unvented systems over 15 litres under Building Regulations Approved Document G3. Vented cylinders are not sealed pressure vessels, so the G3 ticket does not apply. However, the work should still be carried out by a qualified plumber: the immersion electrical circuit must comply with BS 7671 18th Edition, the cylinder must be BS 1566 grade 3 (or stainless equivalent), and the install must be notified under the Water Supply (Water Fittings) Regulations 1999. ERL holds both G3 and Water Regs accreditation regardless of system type.
How long does a vented cylinder replacement take?
A like-for-like vented swap in an accessible airing cupboard takes 3–5 hours. The breakdown is roughly: 30 minutes survey & isolation, 45 minutes drain-down, 90 minutes physical swap, 45 minutes refill and venting, 30 minutes commissioning and paperwork. Older Victorian properties with rigid copper primary pipework can stretch this to 6–7 hours if pipework alterations are needed. Header tank replacement adds 90 minutes. Most jobs are completed comfortably within a single day.
Do you need to replace the header tank at the same time?
Not always — if the loft F&E (feed and expansion) tank is sound, has a working ball valve, a fitted lid and adequate insulation, it can stay. We check it on every cylinder swap. Replacement is recommended if the tank is the old-style red plastic over 25 years old, lacks a sealed lid (Water Regs breach), shows scale or biofilm, or has a leaking ball valve. A replacement F&E tank, fully fitted, runs £325–£465 including a new ball valve and insulation jacket.
Can I convert a vented cylinder to unvented?
Yes — vented-to-unvented conversion is one of the most common London cylinder upgrades. It removes the loft header tank entirely, replaces the vented cylinder with a sealed unvented model, adds a G3 safety group (PRV, expansion vessel, T&P relief valve), and routes a discharge pipe to outside. The cold feed to the cylinder is re-piped from the mains. Cost runs from £2,495 (150L) to £3,295 (250L) including building control notification. See our /unvented-cylinders-london page for the full conversion spec.
What size vented cylinder do I need?
Rule of thumb in London: 35–45 litres per occupant plus 60L per bathroom. A 1-bed flat with a shower is fine on 90–117L. A 2-bed flat is 120–144L. A 3-bed terrace with one bath is 162–180L. A 4-bed semi with two bathrooms wants 210L. Vented systems are slower to recover than unvented (lower turnover rates), so when borderline we recommend sizing up by one capacity bracket rather than down. We always run a sizing check on the survey visit.
What's the difference between direct and indirect vented cylinders?
An indirect cylinder is heated by a coil fed from a boiler primary circuit — boiler hot water passes through the coil and warms the stored water indirectly. A direct cylinder has no coil and is heated only by an immersion heater element (or two). Direct vented cylinders are used in all-electric flats where there is no boiler, or in Economy 7 / off-peak setups. Most London homes with a gas boiler use indirect cylinders so the boiler does the heavy lifting and the immersion is a backup.
How long do vented cylinders last?
Modern copper vented cylinders (BS 1566 grade 3) typically last 15–25 years before either a weld pin-holes or the immersion boss corrodes through. Stainless steel vented units like the Telford Tempest carry 25-year tank warranties and routinely last 30+ years. London hard water shortens cylinder life by 3–5 years versus soft-water areas — the dominant failure mode is scale build-up on the indirect coil reducing heat transfer until the boiler can no longer keep up.
Will my shower be stronger after a vented cylinder swap?
Slightly — a new cylinder with a clean indirect coil will deliver hotter water faster, which lets a thermostatic shower run at a higher set-point with less cold mixing. But the flow rate itself is set by the loft tank's height above the shower head (typically 1–3 m of head = 0.1–0.3 bar). If you want a proper power shower without changing to unvented, the answer is a twin-impeller cold/hot shower pump (£295–£485 fitted) rather than a different cylinder. We always quote both options when relevant.
Do you remove and dispose of the old cylinder?
Yes — old cylinder removal, transit out of the property and disposal at an authorised waste transfer station is included in every quoted price. Copper cylinders go to a metals recycler under our waste-carrier registration; mixed-material units to the WEEE stream. We do not charge an extra disposal or skip fee, and we don't leave the old tank in the front garden. Copy of waste transfer note available on request.
Is the immersion heater replaced with the new cylinder?
We always fit a new 3 kW Incoloy immersion element and dual thermostat on every cylinder swap as standard — at this stage the marginal cost is £165 of parts and 15 minutes of labour, and a brand-new element preserves the cylinder warranty and avoids a separate call-out within the year if the old element fails. Twin-element direct cylinders (Economy 7 setups) get two new elements. New thermostats are set to 60°C top and 65°C bottom by default.
Will my radiators be affected by the cylinder swap?
No — the heating side of the system (boiler, radiators, primary pipework, pump) is independent of the cylinder swap. We do drain the primary loop briefly to disconnect the cylinder coil, but the system is refilled with fresh inhibitor dosed to BS 7593:2019 and re-balanced before handover. If radiator balancing or a system flush is sensible (e.g. cold-bottom rads, sludge evidence), we'll flag it on the survey — see /power-flush-london for the dedicated service.
What warranty do I get on a vented cylinder install?
Copper cylinders carry a 1-year tank warranty as standard, extendable to 5 years if registered with the manufacturer within 30 days (we handle the registration). Stainless cylinders (Telford Tempest, Gledhill Stainless Lite) carry 25-year tank warranties. Workmanship is covered by ERL's own 12-month guarantee on labour and parts. All immersion elements come with a 1-year manufacturer warranty. Warranty paperwork is emailed with the Benchmark logbook within 24 hours of commissioning.

Question not answered? Call 0207 046 1363 and talk to a cylinder engineer directly — no call centre, no triage queue.

Service area

Service area — all London boroughs

Vented cylinder engineers based in central London with same-day cover across all 32 London boroughs and the City. Most jobs booked within 48 hours; emergency leak callouts attended same day. Call 0207 046 1363 any time.

London boroughs we cover

Vented cylinder replacement carried out across every London borough. Heaviest call volumes from Camden, Islington, Hackney, Wandsworth, Kensington & Chelsea, Ealing and Hammersmith & Fulham.

CamdenWestminsterIslingtonHackneyTower HamletsSouthwarkLambethWandsworthHammersmith & FulhamKensington & ChelseaHaringeyEaling

Cylinder cluster

Related cylinder services

Vented work is one part of the wider hot-water-cylinder service. Whether you're comparing systems, planning a conversion, or specifying a smart cylinder, these pages cover the full London cylinder market.

Hot Water Cylinder Replacement (hub)

All cylinder types, sizing, brands and London pricing in one place. Start here if you're still deciding between vented, unvented and smart.

Unvented Cylinders London

Mains-pressure sealed cylinders. G3 qualified installs, Megaflo / Gledhill / OSO. Conversion from vented from £2,495.

Mixergy Smart Cylinder

Wi-Fi controlled cylinder that heats only the volume you need. Solar / battery / heat-pump compatible. From £3,295 fitted.

Completed vented cylinder install with Benchmark commissioning paperwork

Ready to swap that vented cylinder?

From £895 fitted, single-day completion, new immersion and Benchmark logbook included. Fixed-price quote on site before any drain-down. £5M public liability, fully insured, 12-month workmanship guarantee.

0207 046 1363WhatsApp 07456 975436Book online

London 247 Home Services Ltd · Company No. 17120057 · £5M public liability · Water Regs accredited · 24/7 emergency line 0207 046 1363

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