The Resistors on the ADC will get warm when the Relay is ON (Defrost mode).
The Relay should be ON for a maximum of about 30 minutes,
whether or not the Defrost Heater is energized (Defrost T-stat temperature)
The 240k inside the Defrost T-stat is a "marker" used to easily measure the entire Defrost Circuit,
wheather or not the Defrost T-stat is "open" or "closed".