SPECIAL OFFERS
Onyx 500L Red Heating Vessel 1 1/2 1.5 Bar
Onyx 500 litre red heating expansion vessel with a 1 1/2 in connection and 1.5 bar pre-charge.
At a glance
£636.12
£530.10 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 500L Red Heating Vessel is a 500 litre expansion vessel from the Onyx expansion vessel range, intended for sealed heating systems. It accepts the volume increase of system water as it heats, limiting the resulting pressure rise and reducing stress on components such as the pressure relief valve. The vessel is supplied with a 1 1/2 in connection and a 1.5 bar pre-charge.
Signs this part needs replacing
- System pressure rises sharply during heat-up and the pressure relief valve discharges
- Boiler pressure falls repeatedly and the system needs frequent topping up
- The vessel sounds full of water when tapped, indicating a failed internal diaphragm
- Water is present at the air charge valve when the cap is removed
- System pressure is unstable despite correct cold fill and no visible leaks elsewhere
Before you order
- Confirm the calculated vessel volume required for the system matches 500 litres
- Check the 1 1/2 in connection suits the pipework and that the 1.5 bar pre-charge suits the cold fill pressure
- Check the installation space and the support arrangement for the vessel
- Confirm the vessel is intended for the heating circuit and not for potable water
No specification data held for this part.
| Make | Model / assembly | Reference | Years | Fitment |
|---|---|---|---|---|
| SPECIAL OFFERS Pressure Vessels & Accessories | — | — | — |
Documents & drawings
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No documents held for this part. The technical team will source them from the manufacturer — usually the same working day.
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