A like-for-like vented cylinder replacement in London typically costs from around £800, and published UK estimates range from roughly £500 to £1,150 for the straightforward version of the job. Larger cylinders, extra pipework, awkward access or changes to the heating system push the price higher. These figures are indicative published estimates, not a fixed quote for your home.
A vented cylinder is a hot water storage tank fed by a cold water cistern, usually in the loft. Gravity moves the water, so it runs at lower pressure than a mains-fed system. It is common in older London houses, terraces and flats with a traditional airing cupboard setup.
The price usually includes the cylinder, labour, connections, refilling and testing. What changes it is the job itself. Swapping an old tank for the same type in an easy-to-reach cupboard is a different job from moving the cylinder or reworking the pipes.
This guide explains what you are paying for, what pushes the price up, and how to compare quotes fairly.
Need a price for your own home? Request a quote from our London team. Send us your cylinder size and a photo of the airing cupboard.
How Much Does Vented Cylinder Installation Cost in London?
Expect roughly £800 or more for a standard like-for-like replacement in London, with the final price set by cylinder size, access and any extra pipework. UK-wide published estimates for a like-for-like swap sit between about £500 and £1,150. London often lands toward the upper half because of higher labour rates, parking and access constraints.
No honest plumber can give a precise price without knowing what is already in your home. That is why most reputable firms ask for photos or a quick visit first.
What the price is made of
| Cost element | What it covers | Effect on price |
|---|---|---|
| Cylinder supply | The tank itself, sized for your household | Larger and higher-spec cylinders cost more |
| Labour | Draining, removing, fitting, connecting, testing | Longer or harder jobs cost more |
| Immersion heater and thermostat | Electric backup heating, temperature control | Often supplied with the cylinder, but check |
| Pipework | New or altered pipes and connections | Minor tidy-ups are cheap; reroutes are not |
| Removal and disposal | Taking the old cylinder away | Sometimes included, sometimes an extra |
| Extras | New valves, controls, insulation, loft tank work | Depends on the condition of the system |
I have not put a pound figure against each line on purpose. Prices vary between suppliers and jobs, and made-up numbers would only mislead you.
What should be in a good quote
Before you accept any price, check that it states:
- The cylinder make, type (direct or indirect) and capacity
- Whether labour is included
- Whether the old cylinder is removed and disposed of
- Whether pipework changes are included or priced separately
- What happens if the plumber finds a problem, such as a corroded valve
- Any guarantee on the cylinder and the workmanship
If a quote is vague on these points, ask. A very low price that leaves things out can end up costing more.
Vented Hot Water Cylinder Replacement Cost in London
The cheapest and simplest job is a like-for-like swap: the same type of cylinder in the same place, using the existing pipework. Anything beyond that is priced as extra work.
Like-for-like replacement
If your existing vented cylinder is sound apart from the tank, a plumber can drain it, disconnect it, fit the new one in the same spot and reconnect everything. This is the job behind most of the lower published prices. It works best when the airing cupboard is easy to reach and the pipes are in reasonable condition.
Replacing an old copper cylinder
Many London homes still have the original copper cylinder. Over time, copper can corrode, leak at joints or develop a failing coil. A new cylinder usually comes with better factory insulation, which can reduce heat loss. Replacing the tank is often a good moment to renew tired valves and check the immersion heater.
New installation vs replacement
A first-time installation, for example adding a cylinder to a home that currently has a combi boiler, is a bigger job. It may need new pipework, a cold water cistern in the loft, electrical work for the immersion heater and changes to the boiler controls. It should be quoted separately and will cost more than a straight swap.
Vented-to-unvented conversion
Changing a vented cylinder to an unvented one is not the same as replacing it. An unvented (mains-pressure) cylinder needs specific safety devices, a discharge pipe and an installer qualified to fit it. It can also mean pipework alterations, so quotes for this sit well above a like-for-like swap. See our guide to unvented cylinder installation if you are considering it.
How Much Does a Hot Water Cylinder Cost by Size?
A bigger cylinder costs more to buy and can cost more to install, mainly because it is heavier and needs more space. Sizes are measured in litres. Common domestic sizes are 120L, 150L, 180L and 210L.
| Capacity | Rough household fit | Things to check |
|---|---|---|
| 120 litres | One to two people, small flats | Fits tight cupboards; can run short if several people shower close together |
| 150 litres | Small family, two to three people | A common like-for-like size |
| 180 litres | Three to four people, family homes | Needs a taller or wider cupboard |
| 210 litres | Larger households, several bathrooms | Heavier; check floor support and access |
These are rough guides. Your actual need depends on how many people live at home, how often you bath instead of shower, and how many outlets run at once. Always measure the cupboard height and width before you choose.
A like-for-like swap keeps costs lowest because the new cylinder fits the old footprint. Going larger can mean moving shelving, adjusting pipes or, in tight flats, simply not fitting. For more detail, see our hot water cylinder sizes explained guide.
Direct vs Indirect Vented Cylinders
A direct cylinder heats water with an electric immersion heater only. An indirect cylinder heats it through a coil connected to your boiler. Many homes have an indirect cylinder with an immersion heater as backup.
- Direct cylinder: simple, with no boiler connection. Running costs depend on your electricity tariff.
- Indirect cylinder: heated by the boiler through an internal coil, so it works with the central heating system. This is the more common setup in homes with a gas boiler.
Replace like with like unless you have a reason to change. If your current cylinder has two coil connections on the boiler side, you almost certainly need an indirect replacement. Our direct vs indirect cylinder page explains how to tell which you have.
What Affects the Cost of Installing a Vented Cylinder?
Access, pipework condition and cylinder size cause most of the price differences between quotes.
- Cylinder capacity and quality. Larger and better-insulated cylinders cost more.
- Material. Copper is the traditional choice. Other materials are available at different prices.
- Direct or indirect. Indirect models with coils can cost more than direct ones.
- Existing pipework. Old, corroded or awkwardly routed pipes add time and parts.
- Loft cold water tank. The cistern feeds the cylinder. If it is old, cracked or poorly installed, it may need replacing too.
- Immersion heater and thermostat. A new element, or a thermostat upgrade, adds a small cost.
- Location. Cupboards on upper floors or with narrow access are harder to work in.
- Labour time. Draining, removal, fitting and testing take longer when anything is hidden or stuck.
- Removal and disposal. Large cylinders are heavy, and disposal is sometimes charged separately.
In London, parking restrictions, congestion charges and stairs-only access in older buildings can also affect time and cost. A plumber who has worked in your type of property will usually spot these early.
How Does Vented Cylinder Installation Work?
A straightforward replacement is a five-step job: inspect, select, drain and remove, install, then refill and test.
- Inspect the existing system. The plumber checks the cylinder, pipework, cold water cistern and immersion heater.
- Select the correct cylinder. The size, type and connections must match your system.
- Drain and remove the old cylinder. The water supply is isolated, the cylinder is drained, and the old tank is disconnected and taken out.
- Install and connect the new cylinder. The new tank goes in place, with the heating and hot water pipes reconnected, plus the open vent pipe and cold feed. The immersion heater and thermostat are fitted.
- Refill, test and commission. The system is refilled, checked for leaks, and the heating and temperature controls are tested.
Vented vs Unvented Cylinders: Which Is Better for a London Home?
Neither is better for everyone. A vented cylinder is simpler and cheaper to replace, while an unvented one gives stronger, mains-level pressure.
| Feature | Vented | Unvented |
|---|---|---|
| Water supply | Fed by a cold water cistern, usually in the loft | Fed directly from the mains |
| Pressure | Gravity-fed, so often lower | Mains pressure, usually stronger |
| Loft tank needed | Yes | No |
| Typical installation cost | Usually lower | Usually higher |
| Installer requirements | Standard plumbing skills | Specific qualification and safety devices |
| Best for | Homes with an existing vented system and a loft | Homes wanting better pressure, or with no loft space |
Do not call a vented cylinder “mains pressure”. It isn’t. Pressure depends on how high the cold water tank sits above the taps.
When to keep a vented system: if your showers and taps perform well and the setup is sound, a like-for-like replacement is usually the lowest-cost route. When to consider an upgrade: if low pressure is a constant complaint, or you want to remove the loft tank. Our vented vs unvented cylinder guide goes deeper.
Repair or Replace: Signs Your Cylinder Needs Replacing
Replace the cylinder if it leaks from the tank body, shows heavy corrosion or is repeatedly failing. Repair it if only a small, accessible part has failed.
Watch for:
- Water leaking around the base of the cylinder
- Rust-coloured hot water
- Visible corrosion or green staining on copper
- Hot water that runs out quickly or takes too long to heat
- Frequent faults with the immersion heater or thermostat
- Damaged or weeping connections
A faulty immersion heater, a worn thermostat or a leaking valve can usually be fixed without replacing the tank. A leak from the tank itself generally cannot be repaired reliably. If your cylinder is old and needing frequent attention, replacement tends to be better value than repeated repairs. See hot water cylinder repair London and immersion heater replacement for the cheaper options.
How Long Does Vented Cylinder Installation Take?
A straightforward replacement is often completed in a single working day, though the exact time depends on access and the state of the pipework. Some jobs can be quicker, and others take longer.
- Simple like-for-like swap: usually the shortest job
- First-time installation: longer, as it involves new pipework and loft work
- Extra pipework or difficult access: adds time
- Testing and commissioning: always allow time for refilling and leak checks
Your plumber cannot promise a fixed time until they have seen the existing set-up. You should expect some hours without hot water while the old cylinder is out.
Mistakes to Avoid When Replacing a Cylinder
- Comparing quotes that don’t match. One may include removal and disposal while another does not.
- Choosing size by guess. Measure the cupboard first, and think about how many people use hot water at peak times.
- Ignoring the loft tank. An old cold water cistern can undermine a new cylinder.
- Swapping type by accident. Fitting a direct cylinder where an indirect is needed will not work with your boiler.
- Assuming vented means mains pressure. It does not.
- Skipping insulation. A well-insulated cylinder wastes less heat.
Frequently Asked Questions
How much does vented cylinder installation cost in London?
Around £800 or more for a standard like-for-like replacement is a realistic starting point in London. Published UK estimates run from roughly £500 to £1,150, and extra work raises the total.
How much does it cost to replace a vented hot water cylinder?
Published estimates for a like-for-like replacement range from about £500 to £1,150, depending on size, access and pipework. Always request an itemised quote.
How much does a 150-litre hot water cylinder cost?
It depends on the make, material and whether it is direct or indirect. Ask for the cylinder and labour costs listed separately so you can compare accurately.
What size cylinder does a family of four need?
Many families of four use a 180L or 210L cylinder, but it depends on bathrooms and habits. Check your cupboard dimensions first.
What is the difference between direct and indirect cylinders?
A direct cylinder is heated by an immersion heater only. An indirect cylinder is heated by your boiler through an internal coil.
How long does it take to replace a hot water cylinder?
A simple swap is often done in about a day. First-time installs or jobs needing pipework take longer.
Can I replace my cylinder without replacing my boiler?
Yes. In most cases a cylinder can be replaced independently, as long as the new one is compatible with your boiler and controls.
Does a vented cylinder need a loft water tank?
Yes. A vented cylinder is fed from a cold water storage cistern, which is typically in the loft.
Can a leaking hot water cylinder be repaired?
A leaking valve or connection can often be fixed. A leak from the tank body usually means the cylinder needs replacing.
Does installation include removing the old cylinder?
Not always. Some quotes include removal and disposal and some charge extra, so confirm before you book.
Get a Quote for Vented Cylinder Installation in London
If you are weighing up the cost of a new vented cylinder, the quickest way to a reliable price is to share the details. To get an accurate quotation, send us:
- A photo of your current cylinder and the airing cupboard
- The cylinder’s approximate size, if you know it
- Whether it has a coil (indirect) or just an immersion heater (direct)
- Your London postcode
Contact our London installation team by phone or WhatsApp, or ask for a site assessment. We will explain what is included, so you can compare us fairly with any other quote.