This is an old boiler may be over 30 yrs. Pilot light is lit but when i try to on it from timer, it does not fire. room thermostate , pump etc seem to be working as they click and making noises. Going to change the boiler soon but just need some time to get qoutes etc. Will appreciate if somebody can help me out. I have changed the thermocouple many times in the past when pilot light is out. But this time pilot light is working.