Should I add inhibitor or flushing chemical first?

[mk2phil]

About 6 months ago I replaced all the microbore pipework in my house with 22/15mm and changed all the radiators and valves too. Since then, every other month or so I've been draining the system down, adding a new rad in a newly decorated room and then refilling. Becuase I've been frequently taking rads off and replacing, I've yet to add inhibitor to the system.

Coincidentally, I've noticed that even after bleeding the rads I still sometimes hear noises from them - which I now think is probably gas from corrosion forming. I dont think I've caused any major problems - when drained the water flows out freely, still fairly clean, heats up very quickly, drained about 4 times in the last 6-10 months.

After in-depth reading on here I've realised the error I've made and will now be adding X100 shortly. However, before I do this should I add some X300 for a little while, then drain and add the X100 afterwards?

Or should I just add the X100 immediately and not worry about the X300 becuase I added all the new pipework over 6 months ago and its too late now anyway?

OR should I add some X200 to remove any sludge/crap that may have accumulated since I upgraded the pipework before the X100 goes in?

Not sure whats the best thing to do for the system?

Thanks in advance - Phil

 

[kevplumb]

any cleanser is better than none add it run for a couple of weeks

drain refill
run system drain again

then add inhibitor when you refill