Was looking to do a manual flush of my system and couldn't find this cheaper anywhere. Abit pricier than some brands but has really good reviews.
Abit of blurb below:
Sentinel X400 High Performance Cleaner is specifically designed for cleaning older central heating systems. It is a non-acid treatment which restores circulation to radiators and pipework. Its ruthlessly efficient formula shifts built-up magnetite sludge, eliminating cold spots in radiators and restoring proper heat distribution.
Restores systems suffering with circulation problems
Eliminates radiator cold spots
Prepares older systems for the installation of new components
Has a non-acid formula which does not cause pin-holing or leaks
Can be used in all types of indirect heating systems, including those containing aluminium