You will get a very good system clean with both products. However, if the system is especially dirty it is recommended to use the stronger Power Cleaner F8 which will have an increased dispersion effect, even at low temperatures.

Power Cleaner F8 is a concentrated formulation supplied in 500ml bottles, to reduce packaging waste. Just one bottle treats larger systems of 130 litres, 16 radiators or 250 sqm of underfloor systems and one dose is sufficient for cleaning the central heating systems of up to 97% of all UK homes (or larger heating systems).