hi my boiler is approx 4 year old and for last 2 years intermittantly the lock out lamp would come on but lived with it as had several people look at it but everytime they came it worked perfectly money is tight as i had accident at work and couldnt afford to buy parts on a wim without being sure it would fix it but now i have no hot water or heating the lock out lamp comes on and fault code suggests lack of burner ign no ign signal from the full sequence ign device if i get it to fire up i am lucky if it will complete one cycle then as the ch temp cools and it needs to fire up again it doesn't or it may not fire up at all and on the dhw it will fill the bath maybe an inch then cuts out the pump works the fan runs the pressure is good sometimes pushing the reset button it will work but not for any length of time i think the lack of ign is caused by fault elsewhere any help i would be very grateful 
