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Worcester Bosch Ignition Seal Assembly 871861523A0

Worcester Bosch

Worcester Bosch Ignition Seal Assembly 871861523A0

Worcester Bosch ignition seal assembly (871861523A0) for Greenstar Compact and i Series boilers, sealing the ignition electrode to prevent leaks.

At a glance

  • Part type: Gaskets, seals and washers
  • Also known as 1030859
  • This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Manufacturer part no.
871861523A0
GC number
J04-357
Showing prices

£4.46

£3.72 ex. VAT · VAT at 20%

Available to order · 3 working days
Available to order · 3 working days
Not certain it's the right part? The technical team verifies fitment before dispatch — no charge, and it stops a second trip.Call the technical teamSend a technical question

Same-day dispatch

Ordered by 4pm Mon–Fri, 10:30am Sat.

30-day returns

Unused, in original packaging.

What it is

The ignition seal assembly is a Worcester Bosch sealing component that sits at the ignition electrode on the combustion side of the appliance. It creates a secure, airtight joint around the electrode, keeping combustion products on the correct side of the casing and preventing leakage at the burner door. It is used across the Worcester Bosch Greenstar Compact and i Series families, including LPG and natural gas variants.

Signs this part needs replacing

  • A smell of gas or combustion products around the appliance casing
  • Visible sooting, staining or heat damage around the ignition electrode area
  • The seal is brittle, cracked, flattened or has hardened with age
  • The electrode no longer sits squarely, allowing movement at the joint
  • Repeated ignition faults or lockouts traced to the electrode seating

Before you order

  • Check the GC number and appliance serial plate to confirm the seal matches your model before ordering.
  • Compare the part number on the existing seal with 871861523A0, as the same appliance family uses several similar seals.
  • This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.

Not sure which part?

Search by part number, product name or brand — our technical team confirms fitment before anything is dispatched.