Ferroli modena 80e 80 e HELP AGAIN !!!!!!?

ok, eventually i got fed up and called out british gas, fixed charge call out they replaced my gas valve (got me money worth) was working fine for a few days now when dhw or ch call for heat, the power light is on and the water or ch led come on, it clicks a few times but does not even try to ignite, i have replaced the safety thermostat on the pipe but still nothing, can i state that the warning (red) led DOES NOT come on. i have noticed one thing tho when i was fidling with the thermostat and giving it a wiggle, lifting it etc it sparked and fired the boiler dont know if this makes any sense PLEASE HELP, thanks Craig