Why nobody can price your boiler over the internet
Every online boiler calculator asks the same four questions: house size, bathroom count, current boiler type and postcode. None of those tell an installer what the job involves. Two identical semis on the same street in Scunthorpe can differ by a considerable amount because one has a 22mm gas supply and a straight flue route, and the other has a 15mm run from a meter at the far end of the house and a boiler sat in a bedroom cupboard.
That is why we survey before we quote, free of charge, and why the figure we put in writing is the figure you pay. Below is what a competent installer is actually pricing when they look at your property — so you can read any quote you receive, ours included, and understand what sits behind the number.
The cost is roughly three things, not one
The appliance. Entry-level, mid-range and premium boilers differ in build quality, warranty length, parts availability and how quietly they run. An Ideal Logic Max, a Baxi 800 and a Worcester Greenstar 8000 sit at different price points and carry different warranty terms. A cheaper boiler is not automatically a false economy, but a shorter warranty on a heavily used system usually is.
The installation work. Labour, pipework alterations, the flush, the filter, the flue kit, condensate routing, controls, and making good. This is where quotes genuinely diverge, and where corners get cut to win a job on price.
The compliance work. Gas Safe registration, Building Control notification under Part L, manufacturer registration for the warranty, and the benchmark commissioning record. These are not optional extras — they are what makes the installation legal and the warranty valid.
The seven things that move the price most
- Like-for-like swap or a change of type. Replacing a combi with a combi in the same position is the cheapest scenario. Converting from a conventional system with a tank in the loft to a combi means removing tanks, capping feeds, reworking pipework and making good — a substantially bigger job.
- Moving the boiler. Relocating to a garage, loft or utility adds gas, condensate and flue routes plus new pipework and making good. Popular for freeing up a kitchen cupboard, but it is a genuine cost, not a small extra.
- Gas supply pipe size. Modern boilers demand more gas than older ones. If the existing run is undersized for the appliance's rate, it must be upgraded — the length and route of that upgrade can vary the price noticeably.
- System condition and flushing. An older system with black water needs a full power flush, not a chemical dose. It is a day's work in its own right and manufacturers require it before honouring the warranty.
- Flue route and terminal position. A straightforward horizontal flue through an external wall is simple. Vertical flues, long runs through voids, and terminals near windows or boundaries need extra components and sometimes scaffolding.
- Controls and thermostats. A basic programmer differs from a load-compensating or weather-compensating smart control. Better controls cost more up front and reduce running costs by keeping the boiler condensing.
- Cylinder work on system installs. If you are keeping or fitting an unvented cylinder, that is G3-certified work with its own components, discharge arrangement and certification requirements.
Combi, system or regular — which suits your house?
Combi. No cylinder, no tanks, hot water on demand. Ideal for one-bathroom homes and flats, and the most common choice across Scunthorpe, Brigg and Messingham. The limitation is simultaneous demand: run a shower and a bath tap together and flow drops.
System. Boiler plus an unvented cylinder. Strong mains-pressure hot water to several outlets at once, which suits two-bathroom family homes and larger properties in the villages around Brigg and Barton-upon-Humber. It costs more to install and needs cylinder space and G3-certified work — which we hold.
Regular (heat-only). Retains the loft tanks. Occasionally the right answer for large older properties with vulnerable pipework or where mains pressure is poor. Increasingly rare, but we will recommend it where the property genuinely calls for it.
How to compare three quotes fairly
Line the quotes up and check the scope rather than the total. Does each one include a power flush or only a chemical dose? Is a magnetic filter listed? Are new controls included or reusing the old programmer? Is the gas pipe upgrade priced or noted as "if required"? Is Building Control notification and manufacturer registration stated? Is the warranty length written down, and is it parts and labour or parts only?
A quote that is meaningfully cheaper than the others has almost always dropped something from that list. The cost of that omission usually arrives later, as a rejected warranty claim or a blocked heat exchanger.
Running costs and where the savings really come from
Replacing a genuinely old, non-condensing boiler with a modern condensing appliance improves efficiency significantly. But the larger practical gains come from how the system is set up afterwards: a lower flow temperature so the boiler condenses properly, correctly sized radiators, a balanced system, and controls that modulate rather than simply switching on and off. We set flow temperature and controls up at commissioning and explain them to you rather than leaving factory defaults.
Grants and finance
Government schemes for heating upgrades change regularly and eligibility is specific to the household and property. We do not make claims about what you will qualify for. Check the current position on GOV.UK, or through your energy supplier, and we will happily work alongside any scheme you are accepted onto.
What you get from us
A free survey with an actual engineer, an itemised fixed-price quote in writing, the boiler supplied, fitted, commissioned and registered for the full manufacturer warranty of up to 10 years subject to product and registration, Building Control notification handled, and a 12-month workmanship guarantee on top. Family-run, Gas Safe registered 556262, working Monday to Friday, 8am to 5pm across Scunthorpe, Brigg, Messingham, Scotter, Kirton Lindsey, Barton-upon-Humber, Hull, Grimsby and Doncaster.
Frequently asked questions
What affects the price of a new boiler most?
The boiler itself is often less than half the job. The bigger variables are whether you are changing boiler type or position, the condition of the existing system, whether a power flush is needed, gas supply pipe size, flue route, and the controls specified.
Is a swap cheaper than moving the boiler?
Yes, considerably. A like-for-like combi swap in the same position reuses the existing flue penetration, gas run and pipework. Relocating to a loft, garage or kitchen cupboard adds gas, condensate, flue and pipework routes plus making good.
Do I need a power flush with a new boiler?
On an existing system, effectively yes. Ideal, Baxi, Worcester and Vaillant all require a cleaned, inhibited system with a filter fitted. Without documented cleaning, a later warranty claim is very likely to be rejected.
Combi or system boiler — which costs less to run?
It depends on the household, not the badge. A combi suits one bathroom and moderate hot water demand. Two or more bathrooms, or several people showering at once, usually run better and cheaper on a system boiler and cylinder.
Why are quotes for the same boiler so different?
Because they rarely cover the same work. Check whether each quote includes a flush, a magnetic filter, new controls, gas pipe upgrade where needed, Building Control notification and manufacturer registration. Compare the scope, not the headline figure.
How long does an installation take?
A straightforward combi swap is typically one working day. A conversion, relocation or full system change usually runs to two or three days depending on pipework and access.
How long is the warranty?
Up to 10 years on parts and labour depending on the manufacturer, the model and correct registration. The warranty only stays valid with an annual service, so keep that booked.
Do you give a fixed price?
Yes. We survey free of charge, then issue an itemised fixed-price quote in writing — boiler, parts, labour, warranty and timing. No day rates and no extras added at the end.
Next steps
The only reliable way to price your installation is to look at it. Book a free survey and you will get a written, itemised, fixed-price quote — with the scope spelled out so you can compare it against anyone else's.