Hello could someone offer me some advice, was called out to a oil boiler not working, the property had a power cut and when the power was put back on the boiler would not fire up, i have checked the pump and oil and everything is fine i cleaned the photo cell and checked the nozzle, when i turned the boiler on the fan comes on also sparks but there is no ignition which led me to think it was the control box but the boiler does not lock out it just keeps on trying to fire, I still think it might be something else, could someone offer me some suggestion, many thanks. 
