Checking hours…Mon–Fri 7:30am–5pm · Sat 9am–12pm01302 279234Trade account
Worcester Bosch Electrode Set Spark and Ionisation 871860028A0

Worcester Bosch

Worcester Bosch Electrode Set Spark and Ionisation 871860028A0

Worcester Bosch spark and ionisation electrode set, part 871860028A0, for Greenstar compact and system boilers; ignites the burner and proves flame.

At a glance

  • Part type: Electrodes & Ignitions
  • Also known as 1030933
  • This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Manufacturer part no.
871860028A0
GC number
J04-356
Showing prices

£35.82

£29.85 ex. VAT · VAT at 20%

In stock
Cut-off passed — dispatches next working day
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

This is a Worcester Bosch electrode set combining the spark electrode and the ionisation (flame-sensing) electrode for the burner assembly. The spark side generates the ignition arc that lights the gas at the burner, while the ionisation side monitors whether a flame is actually present and signals the control board to keep the gas valve open only while combustion is proven. It is a service item for Worcester Bosch Greenstar compact and system appliances, including LPG and natural gas variants.

Signs this part needs replacing

  • Boiler attempts to ignite but the burner does not light, ending in a lockout
  • Repeated ignition cycles with no sustained flame
  • Flame lights briefly then the boiler shuts down as flame is not proved
  • Visible damage to the electrode tips, cracked ceramic insulators or a distorted spark gap
  • Carbon build-up or corrosion on the electrode body affecting the spark or sensing signal

Before you order

  • Check the appliance GC number and model plate against the compatibility list before ordering, as the same boiler family uses different electrode assemblies across variants.
  • Confirm the part number on the existing electrode matches 871860028A0 or the alternative number 1030933.
  • 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.