Sludge can cause a lot of problems within your system and can cost you abit of money if not caught early enough. But what is it? What causes it? And how do I get rid of it? Well this section should clear things up.
What is sludge? What causes it?
Sludge or black gunk is your heating system itself and is the result of the different metals in your heating system reacting with each other. This happens in all systems very slightly but is more of a problem in systems that are re-introducing fresh water and therefore more oxygen into the system. This includes systems that are leaking or pumping over.
How do I get rid of it?
Well if your central heating system is leaking or pumping over you need to sort that out first. Then the existing sludge needs to be removed by flushing it out. You will usually have to add a desludging chemical to break up any sludge that has turned solid. Otherwise this can block your radiators, boiler, pipework and even jam your pump causing it to burn out. Then you need to add an inhibitor chemical to stop this happening in the future.
Pages of interest: