Gonna be getting some of this gear to seal a leak which I can not get to without hacking my new bathroom to pieces. Long story, but it feeds the towel rail, which is fed under a newly tiled (and UFH) floor, then up a wall sandwiched between a bath and a cupboard.

Tending to sway towards Fernox as it is top of the range, but will the Sentinels and other cheapo brands (eg Screwfix No Nonsense range) be just as good?

Either way, is the injector tube the better one to go for, from an installation point of view? How exactly do they fix to radiator bleed valves without the water pi$$ing out all over the place?