Thanks, any idea where to buy them and what to order ?
There are essentially two things that can be changed:
1 - The one shot fuses that blow at a certain temperature can be replaced with ones that are higher rated, I got mine from the Bay (item 300604641346 but there are other temperature ratings available and Maplin also sell them).
2- The thermal cutout switch that resets once the temperature has dropped a bit again (apparently some people have more issues than others due to poor placement of this or dirty connections causing higher heat near it). They are dirt cheap to replace as well (search Amazon for "2 Pcs KSD301 140 Celsius Normal Closed Ceramic Thermostat Switch")
Check this is the same on the newer model they have just changed to!!!
You also want to insulate the boiler to help maintain mash temperature and help with attaining a boil and keeping it, there are a number of way of doing it but i chose to do it with a foil backed camping mat (Bay item 201138049715) for a neat looking solution (I also ordered some heavy duty velcro strips, VEL60239, but have not attached them yet but they will hopefully work well once cured and not just come off with the heat).
I also just bought a punch bag hook (Bay item 281591029443) and ratchet pulleys (Bay item 321645609840) to hook up in my garage to enable me to drain the bag really easily (the ratchet pulley means that if you are BIAB'ing you can slowly lift the bag to drain and avoid the suction issues you may get from having a urn that is relatively tall compared to its width).
Oh and a stainless steel ruler is always good to measure the headspace, using BIABacus or similar you can then work out the volume of liquid in the urn at any time.