Worcester Greenstar 4000 Heat Exchanger C/W Sump – Refurbished | Part No. 8716121449

The main heat exchanger is one of the most important components in the Worcester Greenstar 4000 boiler, responsible for transferring combustion heat to the central heating and hot water circuit. When it degrades, the boiler loses efficiency, output drops, and fault codes may appear. The Worcester Greenstar 4000 Heat Exchanger Complete With Sump (Part No. 8716121449) is a professionally refurbished replacement that restores full heating performance across the GR4700IW range of 12s–30c System and Combi boilers.

This is a fully refurbished original Worcester Bosch component, supplied complete with the condensate sump — a notable advantage over bare heat exchangers that require the sump to be transferred over separately. Each unit is professionally cleaned, inspected, and performance-tested before dispatch.

Compatible Boiler Models (Worcester Greenstar 4000 Series)

Key Features

• Worcester Bosch part number 8716121449 — direct OEM replacement for Greenstar 4000 series
• Supplied complete with condensate sump — no need to transfer the sump from the old unit
• Professionally refurbished: cleaned, inspected, and tested before dispatch
• Covers all GR4700IW 12s–24s System (NG & LPG) and 25c–30c Combi (NG & LPG) variants
• 12-month warranty included

Delivery & Returns

Orders placed before 1:00 PM (Monday–Friday) are dispatched the same working day. Standard and next-day delivery options available at checkout. Next-day orders placed on Fridays arrive Monday — select Saturday delivery at checkout for weekend delivery. Returns accepted within 30 days if unused and in original packaging.

Note: Installation must be carried out by a Gas Safe registered engineer.