Special Offers Onyx 150L Red Heating Vessel ONYX150LHEAT

The Onyx 150L red heating vessel is a 150 litre expansion vessel from the Onyx Expansion Vessels range, supplied for use on sealed heating systems. It takes up the expansion of water as it heats, limiting pressure rise across the circuit and reducing strain on the boiler and its components. The 1 1/2 connection and 1.5 bar rating suit it to domestic and light commercial heating installations.

• Boiler pressure climbs quickly once the heating is running and drops again as it cools
• The pressure relief valve discharges water during heating cycles
• System pressure needs topping up repeatedly over a short period
• Water escapes from the air valve on the vessel when it is depressed
• The vessel feels heavy or waterlogged, with little or no air charge present

• Confirm that 150 litres is the correct capacity for the system and that there is space to mount the vessel
• Check the system connection matches the 1 1/2 vessel connection
• Verify that the 1.5 bar rating is suitable for the system design pressure
• Review the fitment information above before ordering