Under-radiator valve connection Red Marka ABG PG20 (20 mm) for heating systems

Under-radiator valve connection Red Marka ABG PG20 (20 mm) is a compact fitting engineered for connecting radiators to central heating systems using a concealed lower feed. Designed for standard 20 mm pipework, this under-radiator connection provides a neat and unobtrusive inlet/outlet solution for both domestic and commercial radiator installations. The product is intended to integrate with common heating circuits where a lower, hidden connection is required.

Advantages

This under-radiator valve connection offers a compact design that facilitates a clean installation with reduced visible piping. Built for compatibility with 20 mm pipework, it simplifies the connection process and helps maintain consistent water flow to the radiator. The fitting is suitable for use in tight spaces beneath radiators and supports concealed lower-feed layouts, enabling a tidy aesthetic without compromising hydraulic performance.

Suitable for

• Connecting domestic panel and column radiators with 20 mm inlet/outlet pipes
• Commercial heating installations requiring concealed lower feed connections
• Retrofit projects where visible pipework needs to be minimized
• New-build heating systems using standard 20 mm copper or plastic pipes

Key specifications

• Connection diameter: 20 mm suitable for standard 20 mm pipework
• Type: under-radiator (lower feed) valve connection
• Compatibility: designed for use with domestic and commercial radiators
• Installation location: concealed lower feed beneath the radiator

How to use

Shut off the heating circuit and drain the section to be worked on before installation. Prepare the 20 mm pipes by cutting them square and deburring the ends, then position the under-radiator connection on the radiator inlet/outlet. Secure the fitting according to the radiator manufacturer’s instructions and the type of piping used (compression, push-fit or soldered joint as applicable). Restore the system, refill and purge air from the radiator to ensure correct circulation and check for leaks at the connection.

Usage recommendations

Use matching 20 mm pipe materials and compatible jointing methods to ensure a reliable seal. Verify radiator compatibility and follow local heating installation codes. After installation, perform a pressure check and bleed the radiator to remove trapped air for optimal heat transfer.