SPECIAL OFFERS
Onyx 2L Grey Potable Vessel 1/2 2Bar ONYX2LPOT
Onyx 2 litre grey potable expansion vessel with a 1/2" connection and 2 bar rating for cylinder and thermal store systems.
At a glance
£19.43
£16.19 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 Onyx 2L grey potable vessel is a small expansion vessel for potable water systems, rated at 2 bar with a 1/2" connection. It absorbs the expansion of heated water in unvented cylinders, thermal stores and water heaters, limiting the pressure rise across the system. It sits within the Onyx expansion vessel range.
Signs this part needs replacing
- Water discharging from the pressure relief valve during heating cycles
- System pressure rising sharply when the cylinder or store heats up
- Vessel feels heavy or sounds full of water when tapped
- Corrosion or water staining around the vessel connection
- System pressure needing frequent topping up
Before you order
- Confirm the connection on the existing vessel is 1/2"
- Check the system's operating pressure sits within the 2 bar rating
- Verify the vessel is fitted on a potable water circuit
- Check there is space for the 2 litre vessel and its connection
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| ADVANCED APPLIANCES ETS,ECB,TSD,TSDC,Tsi,TSiC,EM,EMS,SFUTS | — | — | — | |
| ALBION Mainsflow Thermal Store | — | — | — | |
| COPPERFORM Mainsheat Cylinder | — | — | — | |
| HEATSTORE HS10U Water Heaters | — | — | — | |
| HEATSTORE HS15U Water Heaters | — | — | — | |
| MISCELLANEOUS CYLINDER SPARES Cylinder Spares | — | — | — | |
| NU HEAT Energy Master Thermal Store | — | — | — | |
| POPULAR CYLINDER SPARES Cold Water Inlet Controls | — | — | — | |
| SPECIAL OFFERS Pressure Vessels & Accessories | — | — | — |
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.
No documents held for this part. The technical team will source them from the manufacturer — usually the same working day.
No technical questions yet for this part.
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