Grant MPCBS124X 3 Bar PRV With Pressure Gauge Port (3 Port)

The Grant 3 Bar Pressure Relief Valve (MPCBS124X) is a replacement safety valve for Grant Air Source Heat Pump installations. It is a spring-loaded valve set to lift at a fixed pressure, discharging from the sealed circuit when that pressure is exceeded so the system is not over-pressurised. Once system pressure falls back below the set point, the valve should close and reseat. The part is supplied as a Grant spare and carries the alternative number 3206737.

• Water or glycol mixture weeping from the discharge pipe while the system sits at normal running pressure
• System pressure dropping repeatedly and needing regular top-ups
• The valve failing to reseat after a pressure event, leaving a continuous drip at the outlet
• Scale, corrosion or debris visible around the valve seat or outlet
• Discharge pipe running wet or warm during otherwise normal operation

• Confirm MPCBS124X against the installation or service documentation for your heat pump.
• Cross-reference the alternative number 3206737 when checking supplier listings.
• Check that the system's design pressure matches the 3 bar rating of this valve.
• Inspect the sealing face and any washer at the connection point before refitting.