In order to look after your central heating system it is imperative that you protect it from corrosion.
Inhibitor is a liquid chemical that you add to the circulating water. It stops the steel radiators from “rusting” away from the inside and clogging the boiler and pump with black sediment.
Sentinel and Fernox are two good brands of inhibitor which are the market leaders and have been recommended by many users of this site.
Everyday your system is without inhibitor, the steel rads get more and more rusty inside. This creates gas and your radiators will eventually spring pin hole leaks.
MAGNACLEAN /Magnetic filters
You can fit a Magnaclean on any 22mm or 28mm pipe on the return to the boiler which is basically a powerful magnet (costs around £100) and is also well recommended for protecting your system. Boiler Buddy is a similar device, and there are others. A mechanical strainer is also useful for removing non magnetic particles.
A Magnaclean will catch much of whatever is circulating in the system water and so reduce new accumulations or blockages.
If you have a Primatic cylinder you should NOT add inhibitor as there is a small risk of losing the air bubble inside the cylinder which separates the CH water from the domestic hot water. This will result in your hot water being contaminated with chemicals!