hi hopeing someone can help me please i had my heating off for 2 weeks changed rad valve drained system had gas coin meter changed to monthly pay type engineer turned on boiler which blew 3 amp pole socket had issue fixed which was fan faulty then went on to use boiler for hot water which worked ok when i turned heating on it fires up 3 times ignites for few seconds then goes to reset with blue light flashing had 2 plumbers to look at fault but nobody can diagnose the problem im on tight budget as lost my job so didnt want to pay worcester £300 anybody got any ideas i can pass to the plumber?????