This from an "unqualified muppet"...
If it's in a boiler it's inside - some old boilers have a permanent pilot light - many (most I think) have a pilot that lights automatically - some have no pilot at all. Boilers with a pilot usually have a viewing glass to see if its burning.
Usually when there's a call for heat the fan runs and when a pressure switch senses that the fan is working properly the pilot lights - when the pilot is good and hot the main gas valve is opened. Some old, old boilers do not have a fan.
You do not mention the make or model of your appliance...
Good luck...
Peccavi, December 2009
