Navien
Navien Packing Orifice (Outer) 20054479A
Packing orifice (outer) for Navien NCB300 and NCB500 combi boilers, part number 20054479A.
At a glance
- Part type: packing orifice (outer)
- Appliance family: NCB300 and NCB500 combi
£3.91
£3.26 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
The packing orifice (outer) is a Navien component used in NCB300 and NCB500 combi boilers. It forms part of the boiler's water-carrying assembly, where it seals and meters flow at the outer orifice position. It is supplied as an individual part under Navien part number 20054479A.
Signs this part needs replacing
- Water weeping or a visible drip at the orifice joint
- Staining, crusting or scale build-up around the packing
- Hardened, split or deformed packing material
- Loss of system pressure with no other obvious source
- Noise or unstable flow through the affected assembly
Before you order
- Confirm your boiler model against the fitment list above
- Check the serial number of the appliance, as fitment is listed by serial number range
- Verify the existing part number 20054479A on the component being replaced
- Inspect adjacent seals and joints for damage before reassembly
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| NAVIEN NCB300-28K COMBI - (Serial Number 3710) | — | — | — | |
| NAVIEN NCB300-28K COMBI - (Serial Number 3710) | — | — | — | |
| NAVIEN NCB300-37K COMBI - (Serial Number 3734) | — | — | — | |
| NAVIEN NCB300-37K COMBI - (Serial Number 3734) | — | — | — | |
| NAVIEN NCB300-41K COMBI - (Serial Number 3711) | — | — | — | |
| NAVIEN NCB300-41K COMBI - (Serial Number 3711) | — | — | — | |
| NAVIEN NCB500-1S+/32K COMBI - (Serial Number 3924) | — | — | — | |
| NAVIEN NCB500-1S+/32K COMBI - (Serial Number 3924) | — | — | — | |
| NAVIEN NCB500-2S+/41K COMBI - (Serial Number 3712) | — | — | — | |
| NAVIEN NCB500-2S+/41K COMBI - (Serial Number 3712) | — | — | — |
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 — NCB300-28K COMBI - (Serial Number 3710), NCB300-37K COMBI - (Serial Number 3734), NCB300-41K COMBI - (Serial Number 3711)
manualmanualNAVIEN appliance manual — NCB500-1S+/32K COMBI - (Serial Number 3924), NCB500-2S+/41K COMBI - (Serial Number 3712), NCB500-2S/37K COMBI - (Serial Number 3735)
manualNo technical questions yet for this part.
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