Boiler out, and element out after a 1hr descale at operating temp with a 2.5% citric acid solution. Hardly any scale at all; I think the weak citric acid cleaned up the little bit that was there. I noticed that at each point where the gasket failed, there is some electrolysis going on between the stainless bolts, the aluminium rings and/or the flange bit of the boiler. 4x of the boiler bolts around the rings are stuck solid (and I'm not sacrificing the rings this time to get em off...), so they're soaking till tomorrow with a nice dose of WD40. A PITA really considering it's only been three years since the resto. The stainless boiler flange bolts need somehow to be electrically isolated from the aluminium rings. Maybe some plumbers tape over the thread and a plastic washer at either end(?)
