What can I do if my wood boiler keeps tripping the high limit switch?
the fan should be run off of the aquastat with this limit switch only being used as a safety.  If your boiler were to run away and get over the 200 degree limit, the switch will open removing power to the fan, smothering the fire and cooling.  The limit switch has to be manually reset in order for your fan to kick back on.  I am going through a situation where my limit switch is set at 200 degrees, and my aquastat shuts my fans off at 190 to 195, so I have to constantly go out there to reset the limit switch.  My solution for this problem is they make limit switches for different temperatures, and I am going to install a 220 degree limit switch.  Hope this helps!