Power Flush
A procedure during which your central heating system is drained and cleaning solution is pumped around to displace and sludge which has been generated by corrosion within the system. The procedure should cost between £300-£500 to be done as of Q4 2022. A GasSafe engineer is required to carry out this maintenance procedure in the UK.
Source
https://www.diyplumbing.co.uk/power-flush-what-is-it-why-do-i-need-it-how-much-is-it/ (mirror)