Boiler cleaner and inhibitor with UFH heating

longwalks1

it’s time to clean my Worcester Bosch combi boiler and CH system with a cleaner and inhibitor (either Furnox, Adey or Sentinel).  I add it via the Magnaclean filter.  

Last year it was just the boiler and radiators, now we have a Wunda underfloor heating on 2 loops via a manifold.  Will the cleaner and inhibitor just run through those too? 

Im competent in doing the job, just unsure of what to do with regards to the Wunda UFH

thank you in advance 

ThisIsWeird

Yes, all the system water will mix - I don't know of any domestic system where this would not be the case.
The UFH system will be 99% plastic, so unlikely to contribute anything nasty to the water - Ie corrosion and sludge - and the presence of inhibitor in there will have no adverse affect either.
However, what is your actual intention? You are first going to add system cleaner? Which one? Is it a type that will require flushing out afterwards before fresh water and inhibitor is then added? If so, then I suspect you may struggle to flush the UFH easily as it's supplied via a thermostatically-controlled manifold, which I suspect will reduce the flow through it in comparison with your rad system. 
How do you propose to 'flush' your rad system? 'Drain and refill', or to connect a hose and literally 'flush' through?
Hopefully a proper plumber will advise, but I think I'd be inclined to isolate the UFH from the rest whilst doing this cleaning - there are isol valves at the manifold. I'd then add the cleaner, run the rad system for the required period, the flush. Add inhibitor (and a mag filter if not already), run that to collect any remaining suspended sludge, and finally reopen the UFH.
But, I don't know for sure...