Appliances that are hit by lightning may be damaged and still operate. The most the property owner can hope for is noticeable failure, or strange intermittent operation. The damage to operating appliances would be leakage from a carbon track left by an arc. This track will continue to grow and cause more leakage until a complete failure and or a fire occurs. The carbon track grows wider (larger parallel path) and thus lowers the resistance. This now increases the leakage [current] which creates more heat via the formula I squared R.
The quandary for the property owner with the insurance company distills to only damage is covered. To search for these failures is considered maintenance (maintenance is not covered by insurance).
Think Your Home Or Business Is Safe From Lightning Strikes? Think Again.