NO As - not a pressure vessel "2. The failure of any closed vessel (including a boiler or boiler tube) or of any associated pipework, in which the internal pressure was above or below atmospheric pressure, where the failure has the potential to cause the death of any person." And does not meet requirements for explosion "19. An explosion or fire occurring in any plant or premises which results in the stoppage of that plant or as the case may be the suspension of normal work in those premises for more than 24 hours, where the explosion or fire was due to the ignition of any material"

Could be covered underthis though depending if you findings are coorect what you suspect: electrical short circuit or overload causing fire or explosion;