Navien
Navien Pressure Relief Valve 30002251A
Pressure relief valve for Navien LCB 700 and NCB series boilers, part number 30002251A.
At a glance
- Part type: pressure relief valve
Showing prices
£11.26
£9.38 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 30002251A is a pressure relief valve used in Navien LCB 700 and NCB series boilers. It opens to discharge excess pressure from the heating circuit, protecting the appliance and system components from over-pressurisation. It is a serviceable component intended for fitment by a competent heating engineer.
Signs this part needs replacing
- Water weeping or dripping from the discharge pipe when the system is cold
- The valve failing to hold system pressure, with frequent top-ups required
- Visible scale, corrosion or debris around the valve seat or outlet
- The valve not opening when system pressure rises above the set point
- Water tracking down the valve body or staining around the connection
Before you order
- Confirm the boiler model and serial number against the fitment list above
- Check the existing valve for the part number 30002251A where visible
- Verify the system pressure reading and rule out other causes of pressure loss before replacing
- Confirm the discharge pipework is correctly routed and undamaged before fitting
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| NAVIEN LCB 700 COMBI EXTERNAL 21KW (Serial Number 1705) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 21KW (Serial Number 1705) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 28KW (Serial Number 1710) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 28KW (Serial Number 1710) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 36KW (Serial Number 1709) | — | — | — | |
| NAVIEN LCB 700 COMBI EXTERNAL 36KW (Serial Number 1709) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 21KW (Serial Number 1704) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 21KW (Serial Number 1704) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 28KW (Serial Number 1706) | — | — | — | |
| NAVIEN LCB 700 COMBI INTERNAL 28KW (Serial Number 1706) | — | — | — |
Showing 10 of 70 compatible appliances.
Fitment listings are a guide, not a guarantee. Plant-room assemblies get modified on site more often than not. Send us the GC number off the data badge and a photo of the existing valve and we will confirm before anything is dispatched.
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.
manual
NAVIEN appliance manual — LCB 700 COMBI EXTERNAL 21KW (Serial Number 1705), LCB 700 COMBI EXTERNAL 28KW (Serial Number 1710), LCB 700 COMBI EXTERNAL 36KW (Serial Number 1709), LCB 700 COMBI INTERNAL 21KW (Serial Number 1704), LCB 700 COMBI INTERNAL 28KW (Serial Number 1706), LCB 700 COMBI INTERNAL 36KW (Serial Number 1708), LCB 700 REGULAR EXTERNAL 21KW (Serial Number 1474), LCB 700 REGULAR EXTERNAL 28KW (Serial Number 1478), LCB 700 REGULAR EXTERNAL 36KW (Serial Number 1482), LCB 700 REGULAR INTERNAL 21KW (Serial Number 1472), LCB 700 REGULAR INTERNAL 28KW (Serial Number 1477), LCB 700 REGULAR INTERNAL 36KW (Serial Number 1481), LCB 700 SYSTEM EXTERNAL 21KW (Serial Number 1471), LCB 700 SYSTEM EXTERNAL 28KW (Serial Number 1476), LCB 700 SYSTEM EXTERNAL 36KW (Serial Number 1480), LCB 700 SYSTEM INTERNAL 21KW (Serial Number 1434), LCB 700 SYSTEM INTERNAL 28KW (Serial Number 1475), LCB 700 SYSTEM INTERNAL 36KW (Serial Number 1479)
manualmanualNAVIEN appliance manual — NCB-CE 20KW SYSTEM BOILER ERP - (Serial Number 6662), NCB-CE 23KW SYSTEM BOILER ERP - (Serial Number 6663), NCB-CE 24KW COMBINATION BOILER ERP - (Serial Number 0128), NCB-CE 24KW COMBINATION BOILER ERP - (Serial Number 2570), NCB-CE 28KW COMBINATION BOILER ERP - (Serial Number 0129), NCB-CE 28KW COMBINATION BOILER ERP - (Serial Number 2571), NCB-CE 28KW SYSTEM BOILER ERP - (Serial Number 6664), NCB-CE 33KW SYSTEM BOILER ERP - (Serial Number 6665), NCB-CE 34KW COMBINATION BOILER ERP - (Serial Number 0130), NCB-CE 34KW COMBINATION BOILER ERP - (Serial Number 2572), NCB-CE 40KW COMBINATION BOILER ERP - (Serial Number 0131)
manualmanualNAVIEN 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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