Central heating system cleaner - Fernox F3

[shd1970]

I have replaced 3 downstairs drop feed radiators on my existing central heating system and some of the piping also so my system is completely drained except 1 small radiator downstairs.

I plan now to fill the system and add some Fernox F3 Cleaner in the system and run for a period of time, before then draining as much as possible, before then adding some MB1 inhibitor into the tank in the loft.

Is this the right procedure ?

Also, does the F3 need to be completely drained from the system before adding MB1 or will "as much as possible" suffice and not interfere with the MB1 ???

All replies gratefully received.

cheers all !

 

[JohnD]

as you have it drained at the moment, this would be a good time to replace the lockshield valves on the drop-loop radiators with valves with drain-off.

I have fitted them to all my downstairs rads, it is the simplest way to do a thorough drain. They only cost a few pounds each and as you are already drained, it will be a fairly easy job.

 

[bengasman]

Just draining the system to remove the f3 is not enough. The process is similar to a washing machine program.
1 Wash with detergent, and a number of rinses to get rid of the dirt.