Sludge in your heating system
- Radiators cold at the bottom is first warning sign
- Bleeding radiators black coloured water
- Radiators not getting as hot as they used to
What causes sludge?
- It’s when water and steel in radiators oxidize and cause a black substance
I tend to find that its old heating systems that attract more sludge. Maybe because there is a header tank in the loft and more air gets into the system. You tend to find that with a combi boiler, with it being a sealed system less air gets into the central heating. It’s what we call a sealed system, a filling loop is used to fill up the heating system instead of a tank in the loft.
You can put these on the return pipe on your heating system by the boiler. The metal in the sludge attracts to the magnet inside the filter so instead of going into your boiler components the sludge stays in the filter.
You are looking to pay £400.00 to flush your full heating system, this should take between 3-7 hours depending on how bad the system needs treating