I have they been dry fired??.
any
good boiler design would incorporate an interlock to prevent dry firing don't you think? Shows a real lack of engineering expertise and cost cutting.
The dry fire stat should do that but in some cases (repeated pressing of reset) the boilers can overheat. New orange board has a temp delay not allowing reset until back below 55
Esprit has a low water switch They are learning slowly but getting there
I will stand by the new isar the only drawback is that it has to be fitted very well with little or no flux or debris left in system. They dont like being fitted onto old systems (yer council stuff just boiler replacements on 10 year old systems).
Bg had a kneejerk reaction and took them off service listing (they are back on now) A lot of BG engineers didnt understand the working of the boiler (I was one of them back then) but this was the M series not the new one.
I could go on all day but you fit what you like all installers are different so I wont convince some on here.
But if you look at the posts on here there are just as many in about baxi, worcester, glowworm, valiant etc in fact even more so at times!