Halstead tro combie boiler problem?

My halstead trio boiler was totally dead the other day. I looked in the fusebox and discovered there was one switch with the word "boiler" underneath it which was still at ON and another switch exactly the same next to it but didn't say boiler underneath it. I tried to flick it to the ON position but it just pushed back down to OFF again. So I then pressed the tiny little TEST button on the switch and flicked it up and it was working again. Today it's dead again and now both these boiler switches have switched themselves to OFF.