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Quick answer
To compare boiler quotes fairly, check that each one specifies the exact boiler make and model, output, warranty length and conditions, controls, system cleaning, filter, flue, condensate route, gas pipework upgrades if needed, removal of the old boiler, Building Regulations notification and the Benchmark commissioning record. Cheaper quotes often leave out system cleaning, a filter, required controls or gas pipe upgrades, which can turn up later as extras or cause warranty problems. Ask each installer to itemise the same list so you can see where the price differences really are.
Key takeaways
- Compare the full specification, not just the price and boiler brand.
- Check the boiler output is matched to your home, not just the biggest model.
- System cleaning, inhibitor and a magnetic filter should be included and are often warranty conditions.
- Boiler Plus rules in England require certain controls with new gas boilers.
- The installer must notify Building Control, usually through Gas Safe, and give you a completed Benchmark record.
What a good quote should include
The boiler. Make, model and output in kW. See what size combi boiler do I need.
Warranty. Length, whether parts and labour are covered, and the conditions such as annual servicing and a filter. See boiler warranties and annual servicing.
Controls. Room thermostat, programmer and any smart or compensation controls. England’s Boiler Plus rules require a timer and room thermostat, and one of several energy-saving measures on combi installations. See Boiler Plus rules.
System cleaning. Chemical clean or power flush, depending on system condition, plus inhibitor.
Magnetic filter. Brand and fitting. See magnetic system filter explained.
Flue. Type and route, including extensions and any plume kit.
Condensate. How and where it will drain, and whether external runs are insulated.
Gas supply. Whether the gas pipe needs upgrading to supply the new boiler.
Removal and disposal. Old boiler, cylinder or tanks if relevant.
Making good. Filling holes and tidying where old flue or pipework is removed.
Paperwork. Building Regulations notification and completed Benchmark checklist.
Where quotes differ most
- One quote includes a power flush, another only a chemical clean, another nothing.
- One includes a gas pipe upgrade the other has not assessed.
- Different boiler models from the same brand with different warranties.
- Controls: a basic thermostat versus a smart or weather-compensated setup.
- A like-for-like swap versus moving the boiler. See moving a boiler.
Questions to ask each installer
- Did you survey the property, or quote from photos?
- Will you check gas pipe sizing and working pressure?
- What cleaning will the system get, and why?
- Which filter and inhibitor are included?
- How is the warranty registered, and what do I need to do to keep it?
- Who notifies Building Control?
- Is the installer on the Gas Safe Register?
Book with Gasmaster
Want an itemised boiler quote you can compare properly? Gasmaster Plumbing & Heating, Gas Safe registered (220932), installs boilers across Stoke-on-Trent, Newcastle-under-Lyme and Biddulph. Start with our boiler quote or see boiler installation.
Frequently asked questions
Why do boiler quotes vary so much?
Different specifications, installation complexity and business overheads. Comparing itemised quotes reveals the real differences.
Is the cheapest boiler quote a bad idea?
Not necessarily, but check it includes the same work. A low price missing cleaning or controls can cost more later.
Should I get more than one quote?
It is sensible to get at least two or three detailed quotes for a significant job.
What about online fixed-price quotes?
See online fixed-price boiler vs local installer.
Sources
- GOV.UK, Boiler Plus guidance for England
- Benchmark scheme, HHIC (centralheating.co.uk)
- Gas Safe Register, Building Regulations notification (gassaferegister.co.uk)
- BS 7593, water treatment for heating systems (bsigroup.com)
Related services
Abdul runs Gasmaster Plumbing & Heating and has worked on boilers, heating and gas appliances across Stoke-on-Trent since 2005. He is Gas Safe registered (reg. 220932), and these articles come from his day to day work in homes and businesses across Staffordshire, Cheshire and Derbyshire.
