fixin my baxi solo20 pf?

i have a baxi solo 2 pf, havin problems, it comes on for about 30 mins then goes off,all lights go off,turn it off at mains and switch back on still nothin,then i cant get it working until about an hour after,had the heat stat and thermometer changed still doin the same could anyone please help me thanks

horlicks
March 2007