look at the boiler is it firing up. or is there just a blue spark but not firing. if its firing listen to see does the igniter transformer stop buzzing or is it carrying on buzzing after the flame has ignited. if so the spark electrodes need cleaning. there two so clean them both one will be by the flame window the other a bit further away. u need to clean it with sand paper. give it a go then post again if no luck
kash
February 2013