The Worcester Bosch Greenstar 4000 25 kW is a high-efficiency, compact gas combi boiler designed for small to medium homes. It provides reliable heating and instant hot water while keeping running costs low.

Key Features

• Energy efficiency: A-rated ErP for both heating and hot water

• Quiet operation: Sound power level of around 45 dB, making it one of the quieter combi boilers

• Water-saving QuickTap function reduces water waste while waiting for hot water

• Wide modulation range (from 3 kW to 24 kW for central heating) helps manage gas consumption efficiently

• Colour display for easy control and monitoring

• Compatible with wireless control: supports Bosch EasyControl and other RF thermostats

• Intelligent Filling System (optional) helps maintain boiler pressure and detects leaks

• Hot water flow rate: around 9 litres/min at a 40 °C temperature rise

• Compact dimensions: 724 mm (height) × 400 mm (width) × 310 mm (depth)

• Long guarantee: up to 10 years when installed by a Worcester Bosch Accredited Installer

Why It’s a Great Choice

This boiler is ideal for homes with up to one bathroom and a modest number of radiators. Its quiet operation, compact build, and high efficiency make it both comfortable and cost effective. The QuickTap feature and modulating output help minimise waste, while smart control compatibility adds flexibility and convenience.