Filling/Make-up Valve CALEFFI 553640 1/2" with Pressure Gauge

The CALEFFI Filling/Make-up Valve 1/2" with integrated pressure gauge is an automatic device designed to maintain and regulate pressure in closed heating and plumbing systems. It connects to the system via a 1/2" inlet and restores water to the circuit when pressure falls below the set level, while the built-in pressure gauge provides continuous visual monitoring of system pressure. The product is intended for residential and light commercial installations where stable operating pressure and straightforward pressure verification are necessary.

Advantages

This make-up valve combines automatic pressure maintenance with an integrated pressure gauge, reducing the need for separate components and simplifying installation. Its compact 1/2" connection is compatible with common domestic piping, and the integrated gauge allows quick visual checks without additional instrumentation. The unit is suitable for long-term use in closed systems and supports consistent system performance by preventing undervoltage and air ingress that can occur with low pressure.

Suitable for

• Domestic central heating systems requiring automatic pressure compensation
• Small commercial heating or hydronic systems with limited space
• Plumbing systems where visual pressure monitoring and automatic refilling are needed
• Retrofit projects replacing manual filling arrangements with automatic control

Key specifications

• Connection size: 1/2" suitable for standard domestic piping
• Function: automatic filling / make-up to maintain system pressure
• Built-in pressure gauge: provides direct visual indication of system pressure
• Application: closed heating and plumbing systems for residential and light commercial use
• Material and construction: corrosion-resistant components appropriate for potable water and heating circuits

How to use

Install the valve in the supply line to the closed system following pipe orientation and manufacturer installation best practices. Once connected, set the required system pressure according to the heating or plumbing system specifications; the valve will open automatically to admit water when pressure drops below the set threshold and close when the target pressure is reached. Monitor the built-in pressure gauge regularly to confirm correct operation and to detect any persistent pressure loss that may indicate a leak or other issue.

Usage recommendations

Verify compatibility with the system’s maximum allowable pressure and local regulations before installation. During commissioning, check for leaks and proper sealing at all connections. Periodic visual inspection of the pressure gauge and occasional functional checks of the valve mechanism will help ensure reliable operation; if persistent pressure loss or gauge malfunction is observed, consult a qualified technician.