"Had to drain my central heating system down as the water pump needed changing and the valves had seized. Previously dosed 4 years ago and the water that came out was clear with a few particles in suspension. Since dosing the system last time there has been no loss of performance of the radiators or water heat exchanger and the pump runs quietly with this in the system. So have used it again and will continue to use it."
"I always use Fernox and, as others have said, after every drain down the water runs reasonably clear. Great in older systems after flushing. In my experience no simialr product does a better job and this is consistently good so I keep using it."
"This is the only protector that I have used over many years and in several properties, so I cannot compare it with other products. What I can say is - when I drain any system that has had MB-1 installed, the water runs clear without any significant sign of contaminants. That is good enough proof for me."
"Radiator had to come out for new wall panel. On draining found water to be turning dirty. Was over 6 years since serviced with Fernox protector. 10 minutes in car to Screwfix, available in stock, well priced and out in five. Back home, wall panel fitted, radiator painted, Fernox into the system and hopefully another 8 years of service from potterton boiler and system. Great having a screwfix store, extensively stocked and close bye."