Dirty system water is one of the most common causes of heating problems. So on a boiler service, we often test it with an Adey ProCheck kit.
What the test shows
It measures inhibitor level, pH and contamination. Over time, systems build up sludge and magnetite (black iron oxide from corrosion inside the pipes and radiators). That debris wears out pumps and valves, causes cold spots, and damages boiler heat exchangers.
If it fails
Depending on how bad it is, we’ll suggest topping up the inhibitor, a chemical clean, or a full power flush (from £900 inc VAT). Clean water matters even more with modern condensing boilers and heat pumps.
See power flushing and boiler servicing.