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Worcester Bosch Bonded Washer 19.9mm Pack of 10 87161122590

Worcester Bosch

Worcester Bosch Bonded Washer 19.9mm Pack of 10 87161122590

Worcester Bosch bonded washer, 19.9mm, supplied as a pack of 10, for sealing joints on Greenstar and British Gas combi and system boilers.

At a glance

  • Part type: Gaskets, seals and washers
  • Also known as 1030593
  • This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.
Manufacturer part no.
87161122590
GC number
H10-209
Showing prices

£11.69

£9.74 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

A bonded washer manufactured by Worcester Bosch, measuring 19.9mm across. The bonded construction combines a rubber sealing face with a metal backing washer, so it seals a joint while spreading the load of the fastener that holds it. It is used across the Worcester Bosch Greenstar and British Gas appliance families to keep water and gas paths leak-free at the points where components meet.

Signs this part needs replacing

  • A weep or drip at a joint that the washer seals, often visible as a crusty deposit or water staining around the fitting.
  • The rubber face has hardened, cracked or flattened, so it no longer compresses to fill the joint face.
  • Scale or corrosion has built up on the metal backing, preventing the washer from seating squarely.
  • A joint that continues to seep after being tightened, indicating the sealing face has failed.
  • Discolouration or swelling of the rubber after contact with system water or inhibitor.

Before you order

  • Check the GC number and appliance model against the compatibility list to confirm the washer suits your boiler.
  • Compare the previous numbers 8-716-771-259-0 and 87167712590 with the marking on the old part before ordering.
  • Confirm whether the joint also needs a separate gasket or seal, as washers are often replaced alongside other sealing components during a strip-down.
  • 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.