Pilot light lit but no heat (by 3 users)

the pilot's millivolt generator may be at fault.  if you have a meter that is capable of measuring a very small DC voltage, connect it up to the very end of the thermocouple and the copper cappillary. the thermocouple has a welded bead at the very end inside that generates a small DC voltage. Same principle of a J-K thermocouple. Iron constintan  - two dissimiller metals where joined together produce a voltage when heated.  the thermocouple actuates a millivolt electromagnet inside the valve to keep the valve pellet open.  no voltage there it won't actuate the electromagnet.