Calchem is a three in one chemical inhibitor designed to protect central heating systems. Calchem combines a number of competitor products into one simple solution. For more information on this please click here. calchem has a special advanced formula which begins to work upon contact with sludge, limescale, flux and other debris. The fast reacting liquid is water soluble, non-flammable and, more critically, non-acidic. This means it can be used on all types of heating systems including copper and aluminium. More importantly, calchem is environmentally friendly. calchem should be added to your heating system via the filling loop or radiator. It will then break down silt, lubricate valves and pumps, suppress bacteria growth and eliminate the production of gases. Calchem also contains an anti-freeze solution which helps heating systems cope with cold weather. calchem is supplied in 1 litre, 5 litre and 25 litre bottles. 1 litre will be sufficient to treat 10 -15 radiators. If you add any radiators or interrupt the water supply, then you should top up your system with calchem. We recommend that a further litre should be added every 2 years to prolong the life and efficiency of your heating system.