Does it say where the unit was made? Therma-Stor made these units 10 years ago. No boards in them back then that I know about. Running the fan "on" should not be a problem. Sanidry imported from China after that. You may try Badger Systems for more info on parts.
Also the fan could be wired with compressor circuit.
Regards Teddy Bear
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"