Worcester Greenstar Heatslave II External 18/25 2022+ Combi Boiler

Worcester Greenstar Heatslave II External 18/25 2022+ Combi Boiler

The Worcester Bosch Greenstar Heatslave II External 18/25 is a high-performance oil combi boiler designed for outdoor installation. Providing central heating and instant hot water from a single appliance, it is an excellent choice for small to medium-sized properties located off the mains gas network.

With a maximum central heating output of 25kW and a domestic hot-water flow rate of up to 18 litres per minute, this boiler delivers dependable heating and strong hot-water performance without requiring a separate cylinder.

Its durable, weather-resistant external cabinet frees up valuable space inside the property. Integrated frost protection supports reliable operation during cold weather, while the cross-firing burner and one-piece primary baffle provide convenient access for servicing and maintenance.

Key Features

• Maximum 25kW central heating output
• Hot-water flow rate of up to 18 L/min
• Provides heating and instant domestic hot water
• External installation saves valuable indoor space
• Durable, weather-resistant green cabinet
• Integrated frost protection
• Quiet operation
• Digital control interface for accurate operation
• Cross-firing burner design
• One-piece primary baffle for easier servicing
• Convenient front access to internal components
• Easy-access oil and hydraulic connections
• Compatible with selected Worcester Bosch controls
• Solar-compatible
• ErP A-rated for central heating
• ErP B-rated for water heating
• Up to 7-year Worcester Bosch guarantee, subject to eligibility and manufacturer terms

Technical Specification

Why Choose the Heatslave II External 18/25?

The external design makes this boiler particularly suitable for properties where indoor installation space is limited. Its 25kW output provides a balanced combination of heating capacity and hot-water performance, while Worcester Bosch’s service-friendly design helps simplify routine maintenance.

Important Information

• Installation must be completed by a suitably qualified OFTEC-registered heating engineer.
• A magnetic system filter is not included.
• The appropriate flue, controls and installation accessories should be purchased separately unless expressly stated otherwise.
• Worcester Bosch’s extended guarantee is subject to installation, registration and eligibility requirements.
• Boiler suitability should be confirmed by a qualified heating professional before purchase.

Delivery is 6-11 Days