hi , looking for a experienced oil engineer , I - embarrassingly am a gas ( no experience of oil )heating engineer but cannot find any fault finding guide regarding readings to pinpoint lockout problem ie voltages resistance etc ,, danesmoor 15/19 - does fire up - when cold runs for approx 30 mins then locksout - after reset runs approx 5-15mins , have replaced capacitor as old one was leaking ! ,, still the same - cleaned out whole boiler & pump - oil ways - all clear ,, cleaned photocell - still the same ,, fitted new nozzle - still the same ,, waiting on new photocell coming to try - very frustrating as I would be able to find problem with sufficient fault finding data for this boiler - can anyone help ,, wife & kids fed up being cold !! thanks