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Navien O-Ring 20035694A

Navien

Navien O-Ring 20035694A

EPDM O-ring, size 17 x 4, hardness 70, black, for Navien NCB-CE system and combination boilers.

Manufacturer part no.
20035694A
Showing prices

£4.45

£3.71 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; EPDM, 17X 4, 70, BK is a rubber sealing ring manufactured by Navien for use in its NCB-CE range of system and combination boilers. It provides a flexible, watertight seal at the joint or connection where it is fitted, preventing weepage in the water circuit. EPDM construction suits the temperatures and water conditions found inside a domestic heating appliance.

Signs this part needs replacing

  • Water weeping or dripping from the joint where the O-ring sits
  • The ring feels hard, brittle or shows visible cracking when the joint is opened
  • Flattening or distortion of the ring so it no longer sits proud of its groove
  • Black residue, debris or scale build-up found on the sealing face

Before you order

  • Check the boiler data plate to confirm the exact NCB-CE model and output before ordering
  • Confirm the O-ring size and groove it sits in, as dimensions are stated as 17 x 4
  • Inspect the sealing faces of the joint for pitting or damage that could prevent a reliable seal
  • Fit a new ring whenever the joint is disturbed, and check the number of seals required for the job

Not sure which part?

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