Powerflush and 2 leaky radiators - Central Heating job in Oval, South London

Job description

I have 5 radiators (inc 1 towel rail) and have been advised to get a PowerFlush. The towel rail and 1 radiator are leaking slightly on the left hand side, leaving a slightly discoloured (green) stain on floor below. The others look fine but maybe could do with a check.