I need to top up the inhibitor in my system, after having drained down part of it for some radiator work. However, I haven't a clue what sort of inhibitor is currently in there. I suspect that it's a bad idea to bung in anything else without complete flushing out, in case of adverse reaction or something - am I right?
I'm very loathe to drain the whole system down as it's incredibly prone to airlocks (I once had to call out a plumber just to sort that!) so I'd really rather avoid that...
Thanks David