CombiWorcester Bosch Greenstar 4000 25kW
£1,995
fitted price (from)
£34
per month (finance)
Warranty: 10 years
Installation: Next day available
Free smart thermostat
New boiler installation quotes
Compare fixed-price new boiler quotes from Gas Safe registered installers. See what a combi, system or conventional boiler costs fitted, with finance options available.
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Combi
CombiWorcester Bosch Greenstar 2000 30kW
£2,145
fitted price (from)
£37
per month (finance)
Warranty: 10 years
Installation: Next day available
CombiVaillant ecoTEC Plus 832
£2,890
fitted price (from)
£49
per month (finance)
Warranty: 10 years
Installation: Within 7 days
Prices sorted by fitted cost (low to high). Final price confirmed after a survey.
Finance is subject to status and affordability checks. Representative APR varies by provider. Fitted prices assume a straight swap with no major system changes.
When should you replace your boiler?
Most gas boilers last between 10 and 15 years. Past that point, efficiency drops, parts become harder to source and repair bills start to stack up.
If your boiler is over 12 years old, needs frequent repairs, makes unusual noises or your energy bills have crept up without a change in usage, a replacement is usually the cheaper long-term option.
What are the benefits of a new boiler?
Lower energy bills
Modern A-rated condensing boilers run at over 90% efficiency, compared with 60-70% for an old non-condensing unit.
Long warranty cover
New installations typically come with a 10 or 12 year manufacturer's warranty, removing repair costs entirely.
Better controls
Most new installs include a smart thermostat so you can heat rooms only when you need them.
What's included in a boiler installation?
Gas Safe installation
All work is carried out and certified by a Gas Safe registered engineer.
Removal of the old boiler
Your existing unit is disconnected, removed and disposed of responsibly.
System flush
A chemical or power flush clears sludge so the new boiler runs efficiently from day one.
Magnetic filter
Fitted as standard on most installs and usually required to keep the warranty valid.
Warranty registration
Your installer registers the boiler with the manufacturer and notifies Building Control.
Smart thermostat
Many packages include a smart control such as Nest, Hive or Tado.
How does getting a new boiler work?
You answer a few questions about your home — property size, number of bathrooms, current boiler type and where it's located.
You get fixed-price quotes online, usually within minutes, with no obligation and no home visit needed for a straight swap.
You pick your boiler and installation date. Most straight swaps can be fitted the next working day.
The engineer removes the old unit, fits the new one, flushes the system and hands over your warranty and Building Control certificate.
Which boiler type do I need?
Combi boilers heat water on demand with no tank, making them ideal for flats and homes with one bathroom.
System boilers use a hot water cylinder and suit homes with two or more bathrooms where several taps run at once.
Conventional (regular) boilers use both a cylinder and a cold water tank in the loft. They usually make sense only when replacing like for like in an older property.
How do I choose the best new boiler deal?
Compare the fitted price rather than the boiler price alone — labour, flushing, filters and controls can add £500 or more. Then weigh the warranty length, the brand's reliability record and how soon the installer can attend. A slightly higher price with a 12-year warranty is often better value than the cheapest quote with five years.
How can I save money on a new boiler?
Get at least three fixed-price quotes, avoid oversizing the boiler for your home, and book outside the October to January peak when installers are busiest. If cash flow is the issue, 0% or low-APR finance spreads the cost without inflating the total much.
Considering a new boiler:
These guides might help.
Central heating cover
Central heating cover offers the security of having your boiler and heating maintained.
How to choose the right boiler insurance
Boiler insurance is a sensible precaution, but which plan gives you the best deal?
Gas safety tips that could save your life
What should you do if you smell gas? How can you protect against carbon monoxide?
FAQs
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Written by the Grow Your Business energy team · Updated on 21 March 2026