It sounds as if your system is in very poor condition.
Do you realise that when power flushing you have to reverse the flow on each rad several times?
If they are that old and dirty then I would flush with water first to release most of the dirt and then use X800 as the chemical as its non acidic.
Even before power flushing you should drain and refill a few times until the water is fairly clean. But you have to circulate it as, or in between, draining.
As said above, power flushing required considerable skill and experience!
Tony
Do you realise that when power flushing you have to reverse the flow on each rad several times?
If they are that old and dirty then I would flush with water first to release most of the dirt and then use X800 as the chemical as its non acidic.
Even before power flushing you should drain and refill a few times until the water is fairly clean. But you have to circulate it as, or in between, draining.
As said above, power flushing required considerable skill and experience!
Tony
