Automatic Air Vent Valve for Radiators CALEFFI 1" Left (507621)

The Automatic Air Vent Valve for Radiators CALEFFI 1" Left (model 507621) is an automatic venting fitting designed for hot-water radiator systems. It removes accumulated air from radiators and heating circuits to maintain circulation efficiency and reduce operational noise. The valve features a left-hand 1" connection suitable for installation on radiator bodies or return lines where left-threaded connections are required.

Advantages

This automatic air vent provides continuous, unattended elimination of air pockets, helping to prevent cold spots and improve heat transfer. Its compact construction allows straightforward fitting on radiator outlets or returns without altering system layout. The left-hand 1" threading ensures compatibility with left-oriented ports on radiators and manifolds. Materials and design are intended for long service life in typical hot-water heating environments.

Suitable for

• Removing trapped air from residential radiators
• Automatic venting on commercial hot-water heating circuits
• Installation on radiator bodies or return lines with left-threaded 1" ports
• Maintenance-free continuous air elimination in closed heating systems

Key specifications

• Connection orientation: left-hand threaded
• Connection size: 1" thread
• Function: automatic air venting for heating circuits and radiators
• Application: hot-water central heating systems
• Mounting location: radiator body or return line

How to use

Install the valve on the radiator body or return line at the designated vent port with the left-hand 1" thread. Ensure the system is depressurised or isolated according to local installation procedures before fitting. Tighten the valve securely using appropriate tools, taking care not to overtighten and damage threads. After installation, pressurise the system and check for leaks; the valve will automatically release trapped air during normal operation. Periodically inspect the vent for signs of leakage or blockage and replace if necessary.

Usage recommendations

Fit the automatic air vent at a high point or designated vent location to maximise effectiveness. When servicing, follow system isolation and safety procedures and use replacement parts that match the thread orientation and size.