Why are boiler quotes so different? If you’ve had three companies out and come back with prices a thousand pounds apart, it usually isn’t because two of them are trying it on. It’s because they’re quoting for different things. One might include a system filter, a flush and a full warranty registration, while another has stripped all of that out to get the number down.
Comparing quotes properly means looking past the headline figure at what’s actually in it.
Here’s what to check.
What’s often missing from a cheaper quote
When one quote comes in noticeably lower, it’s worth asking what’s been left out. The usual candidates are:
- A magnetic system filter, which most manufacturers require for the warranty to stand
- A system flush or chemical clean before the new boiler goes on
- A new flue kit, rather than reusing the existing one
- Removal and disposal of the old boiler
- Building regulations notification
- Registering the warranty with the manufacturer
- Any pipework upgrades needed to run the new boiler properly
None of these are optional extras dreamed up to inflate a price. Leave the old system unflushed and you can end up pumping years of sludge through a brand new boiler. Skip the filter and you may find the manufacturer won’t honour the warranty when something goes wrong.
The warranty condition most people miss
This is the one that catches people out, and it applies to every major manufacturer rather than any particular brand.
Those long warranties you see advertised, the ten and twelve year ones, are almost never automatic. They typically depend on three things:
- the boiler being fitted by an installer accredited with that manufacturer,
- the boiler being registered within 30 days of installation,
- and the boiler being serviced every year afterwards.
Miss any of those and the cover can drop dramatically, sometimes to as little as twelve months. So a quote that saves you a few hundred pounds up front can quietly cost you years of protection. As a Worcester Bosch Accredited Installer, we can offer the extended warranties on Worcester Bosch boilers, and we handle the registration for you so it doesn’t get forgotten.
Whoever you go with, it’s worth asking directly: what warranty comes with this boiler, what do I have to do to keep it valid, and are you accredited with the manufacturer?
The boiler itself might not be the same
Two quotes might both say “new combi boiler” and mean quite different products. Things that vary between models and manufacturers include:
- The heat exchanger material, with stainless steel and aluminium being the common options and each behaving differently over time
- Build quality and the components used inside
- How easy and cheap replacement parts are to get hold of in a few years
- The standard warranty length, which varies enormously even within a single manufacturer’s range
There are good boilers at several price points, and a cheaper unit isn’t automatically a bad one. But it’s worth knowing which specific model you’re being quoted for rather than just the brand, because entry-level and premium models from the same manufacturer can be very different propositions.
What a proper boiler quote should include
A quote worth comparing should tell you all of this in writing:
- The exact make and model of boiler, not just the brand
- The output in kW
- The warranty length and what’s needed to keep it valid
- Whether a system filter is included
- Whether a system flush is included
- Whether removal of the old boiler is included
- Any pipework, flue or electrical work involved
- Building regulations notification
- How long the work will take
- The total price, and whether it includes VAT
If a quote doesn’t cover these, that isn’t necessarily a red flag, but it does mean you can’t compare it fairly against one that does.
Questions worth asking any installer
These are useful whoever you end up choosing:
- Are you Gas Safe registered, and can I see your card?
- Are you accredited with the manufacturer of the boiler you’re quoting?
- What exactly is and isn’t included in this price?
- What happens if you find a problem once you’ve started?
- Who do I call if something goes wrong in two years?
- Can I see reviews or recent work? Our guide on how to check if a local plumber is good covers this in more detail
When the cheapest quote is the right one
It would be easy for us to argue that you should never take the lowest price. That wouldn’t be honest.
If you’re having a straightforward like for like swap, the boiler is staying exactly where it is, the system is in decent condition, and the cheapest quote is from a Gas Safe registered installer who’s included everything above, then the cheapest quote may well be the right one. Plenty of good local engineers price competitively because they have low overheads, not because they’re cutting corners.
The problem isn’t a low price. It’s a low price that turns out to be for less work, or for a boiler that comes with a fraction of the cover you thought you were getting. Once you’re comparing like with like, go with whoever you trust most.
Frequently Asked Questions
Why are boiler quotes so different?
Usually because they include different things. One quote might cover a system filter, a flush, a new flue kit and full warranty registration, while a cheaper one leaves some of those out. The boiler model itself can also differ significantly even when the brand is the same.
What should be included in a boiler quote?
The exact make and model, the output in kW, the warranty length and its conditions, whether a system filter and flush are included, removal of the old boiler, any pipework or flue work, building regulations notification, the timescale, and whether the total price includes VAT.
Does a cheaper quote mean a worse job?
Not necessarily. A competitive price from a Gas Safe registered installer who has included everything can be perfectly sound. The risk is with quotes that are cheaper because work has been left out, or because the warranty won’t be valid once it’s fitte
Do I lose my warranty if the installer isn’t accredited?
You don’t usually lose it entirely, but you may not get the extended cover. Most manufacturers reserve their longest warranties for boilers fitted by accredited installers, and all of them require registration within 30 days and annual servicing to keep the cover valid.
Get a quote you can actually compare
We give fixed written quotes that spell out exactly what’s included, so you can put ours side by side with anyone else’s and see the difference. If you’d like a rough idea of costs first, our guide to what a new boiler costs has our starting prices, and our boiler sizing guide will help you work out what you need. Or just give us a ring on 07545 198220 and we’ll arrange a free home visit. You can also read more about our boiler installation service.
