Navien
Navien O-Ring 20018079A
Silicone O-ring, 74.4 x 3.1 mm, 70 Shore hardness, for Navien NCB and NPE appliance families.
£4.45
£3.71 ex. VAT · VAT at 20%
Same-day dispatch
Ordered by 4pm Mon–Fri, 10:30am Sat.
30-day returns
Unused, in original packaging.
What it is
A silicone O-ring manufactured for Navien appliances, sized 74.4 x 3.1 mm to G75 specification with a 70 Shore hardness rating. It forms a compression seal between mating surfaces within the boiler or water heater assembly, preventing water or gas leakage at the joint. This O-ring is listed for use across the Navien NCB-CE and NPE-AWE/NPE-SWE ranges.
Signs this part needs replacing
- Visible water weeping or a damp trace around the joint the O-ring seals
- The O-ring is flattened, hardened or has taken a permanent set rather than returning to shape
- Cracking, splitting or surface crazing on the silicone ring
- Swelling or deformation after contact with system water or inhibitor
- Recurring pressure loss traced to the sealed joint
Before you order
- Confirm the appliance model and serial number against the fitment list above
- Check the O-ring dimensions and hardness match the one removed from the appliance
- Inspect the mating surfaces for scoring or corrosion before refitting, as these will damage a new seal
- Verify the joint is the source of the leak before dismantling
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| NAVIEN NCB-CE 33KW SYSTEM BOILER ERP - (Serial Number 6665) | — | — | — | |
| NAVIEN NCB-CE 33KW SYSTEM BOILER ERP - (Serial Number 6665) | — | — | — | |
| NAVIEN NCB-CE 40KW COMBINATION BOILER ERP - (Serial Number 0131) | — | — | — | |
| NAVIEN NCB-CE 40KW COMBINATION BOILER ERP - (Serial Number 0131) | — | — | — | |
| NAVIEN NPE-AWE CE-24A - (Serial Number 5093) | — | — | — | |
| NAVIEN NPE-AWE CE-24A - (Serial Number 5093) | — | — | — | |
| NAVIEN NPE-AWE CE-32A - (Serial Number 5095) | — | — | — | |
| NAVIEN NPE-AWE CE-32A - (Serial Number 5095) | — | — | — | |
| NAVIEN NPE-SWE CE-24S - (Serial Number 5094) | — | — | — | |
| NAVIEN NPE-SWE CE-24S - (Serial Number 5094) | — | — | — |
Showing 10 of 12 compatible appliances.
Documents & drawings
Everything we hold for this part. Where a document exists but we don't hold it, the technical team will source it from the manufacturer — usually the same working day.
NAVIEN appliance manual — NCB-CE 33KW SYSTEM BOILER ERP - (Serial Number 6665), NCB-CE 40KW COMBINATION BOILER ERP - (Serial Number 0131)
manualmanualNAVIEN appliance manual — NPE-AWE CE-24A - (Serial Number 5093), NPE-AWE CE-32A - (Serial Number 5095), NPE-SWE CE-24S - (Serial Number 5094), NPE-SWE CE-32S - (Serial Number 5096)
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