Last night my electricty went off (dont know if this is relevant). This morning my Baxi Bermuda boiler was not working- fire front is working but when I go to restart the back boiler is only ignites for around 40 secs then turns itself off again. Have followed the instructions on sheet - re turn grey knob - wait 3 mins and try again - this does not work either - am now slowly turning into an ice pole. Any ideas - ?