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Navien O-Ring 20030919A

Navien

Navien O-Ring 20030919A

EPDM O-ring, 17 x 4, specification 70, black, for Navien NCB combi and system boilers.

Manufacturer part no.
20030919A
Showing prices

£3.91

£3.26 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 Navien O-Ring 20030919A is an EPDM sealing ring measuring 17 x 4 with a 70 specification, supplied in black. It is fitted to Navien NCB combi and system boilers to seal a mating joint on the appliance and prevent water loss at that connection.

Signs this part needs replacing

  • Water weeping or dripping from the joint the O-ring seals
  • Visible cracking, splitting or perishing of the rubber
  • The ring has flattened or hardened and no longer sits proud of its groove
  • Scale or debris trapped on the ring preventing a clean seal
  • System pressure dropping repeatedly with no other obvious cause

Before you order

  • Confirm your boiler model and serial number against the fit list
  • Check the O-ring seat or groove dimensions match 17 x 4
  • Inspect the mating surfaces for corrosion or scoring before refitting
  • Check whether more than one O-ring is needed for the job

Not sure which part?

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