The Worcester Bosch Greenstar 4000 Natural Gas Combi Boiler (25kW) is a super quiet powerhouse, building on its predecessor with an enhanced look and enhanced performance. Notably intuitional, this boiler boasts an innovative design, featuring a full-text colour display and RF control compatibility.

Installers will appreciate the speed and simplicity of fitting, thanks to the pre-piping jig and rear piping as standard, as well as easy servicing access from the front. With its wide modulation range, it offers top-tier energy efficiency, reducing gas consumption for eco-conscious homeowners. Confidence in quality is assured with a standard 7-year guarantee, extendable to an impressive 10 years with certain additions. Perfect for seamless integration, it facilitates a fuss-free SimpleSwitch from earlier models like the Greenstar i, i Junior, and Si.

• Output: 25kW
• Super quiet operation enhances home comfort
• Quick installation and easy servicing with front access
• Efficient: wide modulation range reduces gas use
• Guarantees from 7 to 10 years with system filter
• Intuitive full-text colour display for ease of use
• Compatible with RF controls for enhanced control

When installed by a Worcester Bosch Accredited Installer with a Greenstar System Filter. The Greenstar 1000 and Greenstar 2000 guarantee is available as standard to both loyalty scheme members and non-WAI's, when fitted with any brand of system filter. Terms and conditions apply.