Worcester Greenstar 4000 System Boiler 12-24kW Range

The Worcester Greenstar 4000 System Boiler range (12-24kW) provides efficient central heating solutions for homes with stored hot water cylinders. Available in **12kW, 15kW, 18kW, 21kW and 24kW** models, these **A-rated condensing system boilers** feature identical compact dimensions with built-in pumps and expansion vessels for versatile installation in space-limited locations.

Key Features

• Compact Design: Uniform 724 x 400 x 310mm footprint across all models fits kitchens and cupboards.
• Wide Power Range: 12-24kW outputs suit small to large properties with cylinder systems.
• Integrated Components: Built-in pump, expansion vessel and optional diverter valve simplify installation.
• ErP A-Rated: High efficiency performance meets latest energy regulations.
• EasyControl Ready: Compatible with Bosch wireless controls and programmers.
• Quiet Operation: Low noise levels suitable for living areas (up to 42dB).

Technical Specifications

Why Buy

The Greenstar 4000 System range offers consistent quality across five power outputs, ensuring the perfect match for any home size while maintaining the same compact, installer-friendly design. Built-in components reduce installation time and A-rated efficiency delivers running cost savings. Worcester Bosch provides 7-year guarantees on all models when installed by Gas Safe engineers.

Suitable For

• Small to large homes requiring system boilers with hot water cylinders.
• Properties needing compact, high-efficiency heating solutions.
• New builds, replacements and extensions across various property sizes.

Select your power requirement from Britain's best-rated system boiler range for reliable, efficient heating performance.

Please note: Delivery times may vary depending on location, with specific details outlined below.

Standard Delivery

UK Mainland 

• Delivery Time: 2–4 working days
• Free Delivery on most orders
• £4.95 for small items
• £69 for Solar Panels, Batteries and other specialized large items delivery

Express Delivery

UK Mainland

• Delivery Time: 1–3 working days
• Free Delivery
• £4.95 delivery for small items

Channel Islands

• Postcodes Covered: GY*, IM*, JE* 
• Minimum Order: £50
• Delivery Fee: £70

Northern Ireland, Offshore Territories & Scottish Islands 

• Postcodes Covered: BT*, HS*, KW, ZE
• Minimum Order: £50
• Delivery Fee: £35

Same Day Delivery 

• Eligible Postcodes:
  E*, EC*, N*, NW*, SE*, SW*, W*, WC*, HA*, UB*, EN*, IG*, RM*, KT*, SM*, CR*, BR*, DA*, TW*
• Minimum Order: £50
• Same Day Delivery Fee: £60
• Special Requests or Locations:
  For areas outside these postcodes or urgent quotes, please email orders@qualityheating.co.uk and we’ll do our best to accommodate.

Collections

Want to collect your order instead?You’re welcome to do so — just email us at orders@qualityheating.co.uk or message us via WhatsApp with your preferred collection time, and we’ll confirm the details.

Collection address: 284 Water Rd, Unit 9, London, HA0 1HX