Hi system3,
Yes, using Fernox 4 would be worth trying. Just wondering have you used Oxypic from Dunsley Heat? I put two bottles worth in the system via the feed and expansion tank and the dripping continued. Would you regard Fernox 4 as more effective than Oxypic?
In any case, I have two tubes of Fernox Superconcentrate Cleaner 3 that I got for €5 each at the local B&Q. Would you recommend cleaning out the system first with Cleaner 3 to flush out the black Oxypic before injecting the Fernox Leak Sealer 4?
I've got a silicone gun, so just need to price the Leak Sealer 4 locally.
Thanks for your advice,
Brian