Grant Pressure Relief Valve Prv 3Bar Mpcbs50 Mpcbs124x

Was 2.5bar Indoor/Outdoor V3/Vortex Combi Indoor htg only Vortex Outdoor = MPCBS50X

Grant Pressure Relief Valve 3bar

The primary function of a safety valve or pressure relief (PRV) is to protect property and life. 
Because a PRV is often the last device to prevent catastrophic failure under pressure conditions, it is important that the valve always works i.e. it must be 100% reliable. 
Pressure relief valves should be installed wherever the maximum allowable working pressure of a system or pressure containing vessel is likely to be exceeded, particularly under fault conditions due to the failure of an expansion vessel.

In domestic heating systems, pressure relief valves are incorporated in the boiler or heating circuit to prevent pressure building up to dangerous levels by releasing the excess pressure through the pressure discharge pipe. It is therefore vital that an approved part is used as it is a safety device.

Grant Pressure Relief Valve 3 Bar – MPCBS124X

Essential Safety Component for Grant Boilers | Genuine Replacement for MPCBS50 & MPCBS124X

Protect your Grant boiler system from overpressure with the Grant Pressure Relief Valve (PRV) 3 Bar – MPCBS124X. This genuine replacement safety valve is designed to automatically release excess pressure from the central heating circuit, helping to prevent damage to internal components and pipework. Suitable for various Grant Vortex Combi and System boilers, this PRV is a critical component for safe and efficient boiler operation.

Ideal for heating engineers and competent DIYers performing system maintenance or repairs, this part replaces older versions including MPCBS50, offering reliable protection and peace of mind.

 Key Features & Benefits

• Genuine Grant Part – MPCBS124X
  Official replacement pressure relief valve, manufactured to original Grant specifications.

• 3 Bar Factory Calibrated Pressure Rating
  Automatically opens to discharge water if system pressure exceeds safe limits.

• Replaces Previous Versions
  Compatible with and replaces older Grant PRVs including MPCBS50.

• Integral Safety Mechanism
  Essential for protecting heat exchangers, pipework, and other system components from overpressure.

• Compact & Robust Design
  High-quality brass and polymer construction built for durability and reliability in sealed systems.

• Easy Installation
  Designed for a direct fit within Grant boiler models—no modifications required.

Compatible Grant Boiler Models

The MPCBS124X Pressure Relief Valve is commonly used in a range of Grant Vortex and VortexBlue oil-fired boilers, including:

• Grant Vortex Combi 21kW / 26kW / 36kW

• Grant Vortex Eco and Pro models (internal and external)

• Grant System Boilers fitted with 3-bar sealed systems

Not sure if it’s the right part? Contact our friendly team with your boiler’s serial number—we’ll confirm compatibility for you.

 When Should You Replace the Pressure Relief Valve?

Replace the PRV if:

• Water is leaking or constantly dripping from the discharge pipe

• You notice boiler pressure frequently rising above 3 bar

• The valve fails to reseal properly after activation

• You're servicing the expansion vessel or repressurizing the system

A faulty or stuck PRV can cause water loss, pressure issues, and even damage to your heating system—timely replacement is crucial.

 Technical Specifications

• Part Number: MPCBS124X

• Replaces: MPCBS50

• Manufacturer: Grant UK

• Type: Pressure Relief Valve (PRV)

• Opening Pressure: 3.0 bar

• Material: Brass body with rubber diaphragm and plastic cap

• Connection: Typically ½" BSP male thread (check boiler manual for confirmation)