Electrical Industries works does strongly recommend the use of a surge protector with pellet units as an added protection. Some spikes such as are caused by lightning strikes and the like may still cause damage to the board as they would to most any electrical appliance. An internal short could also cause a fuse to blow. In most cases a blown fuse from external spike would not cause damage to the unit. Should there have been damage to the electrical system the most likely symptoms would be;
1. Additional fuses blowing as soon as the unit is plugged back in.
2. Fuse blowing when on button is pushed.
3. A component running when stove is plugged in without turning the unit on (most common would be the room air blower, the cartridge heater, or the auger motor). In some cases, provided the unit was not damaged but is not acting correctly the control board may be “rebooted” or reset back to its normal operating parameters, in this case normal function may be restored without replacing components.