Even when the boiler appears to be functioning efficiently, and other radiators in the system maintain the required temperature, one or more radiators are cold at the bottom yet warm at the top.

The most common cause of cold spots is a build-up of iron oxide sludge that has accumulated at the bottom of a radiator and is restricting the flow pattern of heated water.

Clean the system with either X800 Jetflo in conjunction with powerflushing or X400 Sludge Remover. X800 Jetflo used with powerflushing is the remedy of choice and will always provide the best results in terms of speed and efficiency. Where powerflushing is not an option clean with X400 Sludge Remover for 2 hours, but where heavier fouling is expected, a longer period of up to 4 weeks will produce better results.

Once the system has been cleaned, add Sentinel X100. Sentinel X100 will prevent corrosion and the formation of iron oxide sludge.