If your boiler fails to fire up after a few attempts, you should call an HVAC specialist. Seeking help from a professional is suggested whenever you’re dealing with a system that includes highly combustible materials and electrical circuits.
When your boiler doesn't fire up, it’s often due to the pilot light going out. The first thing to check when that happens is the gas supply. If you have gas, turn off the supply, and contact an HVAC specialist that can check the boiler safely and uncover potential problems.
In addition to an inadequate gas supply, the most common problem areas, according to ComfortPro, Inc., include a buildup of dirt or grease, a worn out or damaged thermocouple, and bad electrical connections. Attempting to address any of these areas yourself is dangerous and could invalidate any warranty on the boiler.