C CI Xtramax Ultracom Filling Cock 2000801907 

Glowworm Filling Cock 2000801907

For use with the following Glowworm boilers;

A filling cock function is to help you repressurise the boiler if your pressure is too low. However, this in itself is something you shouldn’t have to do too regularly. If you think you’re having to top up your boiler too often – usually more than twice a year – then you might have problems like leaks in your system.