AEC AD Series Operation And Installation Manual page 61

Remove the four (4) 10-32 bolts securing each heater mounting
plate. Slide out the heater.
To clean the heater/cooling coil, use compressed air or a steam
cleaner to blow the dust off or clean any oily residue on the coil.
Re-install the new heaters in reverse order. Install new heater
gaskets and securely tighten all fasteners.
Re-install the Cooler/Filter housing and securely tighten all bolts.
CAUTION!
Heater loops should not touch each other.
"Hot spots" lead to premature heater failure!
Re-install the wiring based on the sketch you made earlier.
Secure the heater access cover on the side of the dryer.
- Notes -
AD Series Dehumidifying Dryers Page 61