Boilers
Combi Boiler Installation in Liverpool: Tanks Out, Instant Hot Water In
Converting from a cylinder and tank system, or replacing a tired combi, we check your mains flow and pressure properly first so the boiler we fit actually keeps up with your showers.
Gas Safe registered no. 576059 · combi boilers fully fitted from £1,299 · fixed written price before any work starts
Gas Safe registered
Registration no. 576059 · licence no. 3715984
Fixed written prices
Agreed before work starts, no hourly rates
Boilers from £1,299
Fully fitted, immediate installation available
FREE Gas Safety Certificate
With every new boiler installation
Open 7 days
Mon–Sun, 8:30am–5:30pm
Overview
What This Service Is, and Who It Is For
What it is
A combi (combination) boiler heats water directly from the mains on demand, with no cold water tank in the loft and no hot water cylinder in the airing cupboard. Combi installation is either a like-for-like replacement of an existing combi, or a conversion from a conventional tank-and-cylinder system, which involves removing redundant tanks and pipework, capping off old feeds correctly, and re-piping the house to a single sealed system.
Who it is for
Households with one bathroom, or two bathrooms rarely used simultaneously, who want instant hot water without waiting for a cylinder to reheat, and anyone converting from an old gravity-fed system who wants the loft space and airing cupboard back. Also common for smaller households and flats where space for a cylinder is limited or not available at all.
When you need it
Conversion work is best planned when you have time to have the loft cleared and the airing cupboard emptied, since both need access. A like-for-like combi swap is quicker and can usually be arranged with much less notice, including on the day if the existing boiler has failed.
Why it needs a registered engineer
A combi is only the right choice when the incoming mains water can actually support it. Flow rate and pressure vary block by block across Liverpool depending on the age and diameter of the supply pipe and the water company's local network, so testing your actual mains supply before recommending a combi is not optional, it is the difference between a boiler that performs well and one that disappoints on day one.
The cost of leaving it
What Happens If This Gets Left
A combi conversion done without checking the basics first is how people end up with a shower that goes cold when someone runs a tap downstairs.
Risks and escalating costs
- Fitting a combi on a low mains flow rate delivers a genuinely weak shower, and no amount of boiler output on the specification sheet will fix a supply problem at the mains.
- Removing tanks and cylinder without capping the old pipework properly leaves redundant dead legs that can harbour stagnant water and, over time, cause smells or contamination.
- Leaving old cold water tank supports and pipe runs in the loft when they are no longer needed is untidy and can obstruct loft insulation, storage or future work.
- Skipping a proper power flush before conversion means sludge from the old system's radiators and pipework circulates straight into the new combi's compact heat exchanger, which is far more prone to blocking than an old cylinder-based system.
- Undersizing the combi for the property's actual hot water demand at peak times, typically weekday mornings, means the household runs out of patience with it fast.
Mistakes we are called out to fix
- Choosing a combi purely because it is cheaper to fit than a system boiler, without checking whether the household's hot water use actually suits one.
- Not testing incoming mains pressure and flow rate before recommending or agreeing to a combi installation.
- Assuming every combi conversion is a same-day job; removing tanks, cylinder and making good ceilings and airing cupboard space properly takes longer than a like-for-like swap.
- Leaving old tank brackets, unused pipework or an empty cylinder cupboard unfinished, which looks unresolved even once the new boiler is working.
- Ignoring the loft insulation disturbed by removing a tank, which needs putting back correctly rather than left bunched up around the loft hatch.
Our process
How We Carry Out the Work, Step by Step
- 1
Step 1: Mains water test and survey
We test the incoming mains flow rate and static pressure at the property, count bathrooms and outlets, and check the existing pipework and flue options before recommending a combi at all.
- 2
Step 2: Written specification and fixed price
Boiler make, model and output, whether the job is a like-for-like swap or a full tank-and-cylinder removal, pipework changes, making good, and the total price, all agreed in writing before work starts.
- 3
Step 3: Removal of tanks and cylinder (conversions only)
Cold water tank and hot water cylinder are drained and removed, redundant pipework is capped safely, and the loft and airing cupboard are left tidy with insulation reinstated correctly.
- 4
Step 4: Installation, flush and re-piping
The system is flushed to clear existing sludge, pipework is re-run to a single sealed system where converting, and the new combi is mounted, flued and connected to gas, water and electrics.
- 5
Step 5: Commissioning, testing and handover
The boiler is commissioned to the manufacturer's settings, combustion is tested, hot water flow at the taps is checked against expectation, and you get the Benchmark record and a free Gas Safety Certificate.
What you get
The Difference It Makes
Instant hot water, no waiting for a tank to reheat
A correctly sized combi delivers hot water on demand at any time of day without needing to plan around cylinder recovery time.
Space back in the loft and airing cupboard
Removing the cold tank and cylinder reclaims genuine storage space, useful in smaller Liverpool terraces and flats where every cupboard counts.
Mains pressure tested before we recommend anything
We check your actual incoming flow rate and pressure rather than assuming a combi will suit the property, so the recommendation is based on your supply, not a generic answer.
Simpler system, fewer failure points
No cold water tank, no cylinder, no vent pipe or overflow to maintain, which means fewer components that can leak or fail over the years.
One fixed written price
The tank and cylinder removal, making good, pipework and boiler are all itemised and priced up front, whatever the job involves.
Free Gas Safety Certificate included
Every new combi installation comes with a free Gas Safety Certificate as part of the handover.
In detail
Combi Conversions and Combi Replacements in Detail
The question we always answer before quoting a combi is not 'which boiler' but 'will your mains supply actually support one properly'. Incoming flow rate and pressure differ significantly across Liverpool depending on the age of the street's water main, the diameter of the supply pipe into the property, and how many properties share that supply. A Victorian terrace on an older, narrower main can have noticeably lower flow than a newer estate on a modern network a few streets away. We measure this at survey stage with a flow test at an outside tap or the kitchen cold tap, and if the numbers are marginal we will say so honestly rather than fit a combi that disappoints.
Converting from a tank-and-cylinder system involves more than unbolting the boiler. The cold water storage tank in the loft, the vent pipe, the overflow, and the hot water cylinder in the airing cupboard all need draining, disconnecting and removing, and the pipework that fed them needs capping properly rather than just left dangling. Loft insulation disturbed by removing the tank should be reinstated properly across the whole loft floor, not just patched around the hatch, otherwise you lose some of the benefit of the conversion in higher heat loss through the loft.
Sizing a combi correctly is about peak simultaneous demand, not headline litres per minute. A single-bathroom household with occasional guest use is well served by a mid-output combi. A household with two bathrooms that are sometimes used within the same fifteen-minute window at busy times, such as weekday mornings before school and work, needs either a higher output combi matched to a genuinely strong mains supply, or an honest conversation about whether a system boiler with a stored cylinder would actually serve them better despite the extra space it takes.
Making good after a conversion matters for how the finished job looks, not just how it performs. That means patching the ceiling where a tank has been removed if it was in a loft above a landing, reinstating any airing cupboard shelving where practical, and leaving the boiler's new position tidily piped rather than routed the shortest possible way regardless of appearance. A combi installed in a kitchen cupboard should not look like an afterthought once the door is closed.
Residential and commercial properties
Combi conversions are especially common in Liverpool's smaller terraces, flats and semis where loft and airing cupboard space is at a premium. In larger homes with more than one bathroom in regular simultaneous use, we will tell you plainly if a system boiler is likely to serve the household better before you commit to a combi.
Variations of this service
Like-for-like combi replacement
Existing combi swapped for a new one in the same position, typically the quickest combi job with minimal disruption.
Full tank and cylinder removal conversion
Cold tank, vent pipe, overflow and hot water cylinder removed, pipework re-run to a single sealed system, loft and airing cupboard made good.
Combi relocation within the property
Moving the boiler to a more convenient position, such as a kitchen cupboard, during a renovation, with a new flue route agreed in the written quote.
Combi to combi upgrade with improved controls
Replacing an older, less efficient combi with a modern condensing model plus smart or weather-compensating controls to reduce running costs.
Materials, parts and equipment
- Vaillant, Worcester Bosch, Baxi, Heatline and Main combi boilers
- Copper and press-fit pipework with full-bore isolation valves
- Magnetic system filter fitted as standard
- Loft insulation reinstatement following tank removal
- Programmable, wireless and smart thermostats
- Condensate pipework installed to current building regulations
Questions
Combi Boiler Installation: Frequently Asked Questions
How much does a combi boiler installation cost in Liverpool?
Combi boilers are fully fitted from £1,299 for a like-for-like replacement. A full tank-and-cylinder conversion costs more because of the removal, capping and making good involved. You get an itemised written quote before any work starts.
Is a combi boiler right for my house?
It depends on your mains water flow rate and pressure and how many bathrooms you use at the same time. We test your actual mains supply during the survey and will tell you honestly if a combi is not the best fit before quoting one.
What happens to my old tank and cylinder?
They are drained, disconnected and removed as part of the conversion, the redundant pipework is capped properly, and we reinstate loft insulation and tidy the airing cupboard space before we finish.
Will converting to a combi mean weaker showers?
Not if your mains flow rate supports it, which is exactly what we test before recommending a combi. If your mains supply is genuinely limited, we will tell you so and discuss whether a system boiler with a cylinder would suit the property better.
How long does a combi conversion take compared to a straight swap?
A like-for-like combi replacement is often done in a day. A full conversion involving tank and cylinder removal, re-piping and making good typically takes longer, and we confirm the expected timescale in the written quote.
Can two showers run at once on a combi?
It depends on the boiler's output and your mains flow rate. Some higher-output combis on a strong mains supply cope reasonably well; on a limited supply, running two outlets together will reduce flow at both. We will give you an honest answer for your property rather than a generic one.
Do I get a certificate after installation?
Yes, every new boiler installation includes a free Gas Safety Certificate along with the Benchmark commissioning record, and we register the manufacturer warranty on your behalf.
Do you install combi boilers across all of Merseyside?
Yes, across Liverpool, Knowsley, Halton and St Helens, including Huyton, Prescot, Widnes, Runcorn, Crosby, Woolton and Newton-le-Willows. We answer the phone seven days a week, 8:30am to 5:30pm, and we tell you the same day whether we can get to you.
Still not sure? Send us the details or ring 07523 738285.
Your next step
Get Your Fixed Price in Writing
Send us the details and we'll come back with a clear price, or ring now if you're without heating or hot water.
- Gas Safe registered no. 576059 · licence no. 3715984
- 25 Bardley Cres, Tarbock Green, Liverpool L35 1RJ
- 07523 738285 · 0151 384 5908
- info@harrisonejonesheating.co.uk
- Mon–Sun, 8:30am–5:30pm
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Or call us direct on 07523 738285 · 0151 384 5908