From the Heartland website:
A:
For the Dometic brand ice maker
Excerpted from Dometic REFRIGERATOR BULLETIN R69/2C JANUARY 2002 DON'T FORGET TO WINTERIZE YOUR ICE MAKER
WINTER OPERATION
Your refrigerator is equipped with a heater tape wrapped around the water solenoid valve and outlet water tube. During cold weather operation below 32 degrees F (0 degrees C) the automatic temperature switch will turn the heater tape "ON" automatically. If the recreational vehicle is in storage and the DC power is turned "OFF" there will be no 12V DC present to operate the heat tape; therefore, it will be necessary to drain the ice maker. If temperatures are expected to reach or exceed 0 degrees F (-18 degrees C) the ice maker must be drained to prevent component damage and leaks.
HOW TO DRAIN THE ICE MAKER
Note: Water, compressed air and AC power are required to drain the ice maker. Draining of the ice maker must be done by a qualified service technician.
- If the RV will not be in use for an extended period of time or put into storage, the ice maker should be drained and dried. This will prevent water from freezing in the solenoid valve or becoming stale and producing bad tasting ice.
- Close the shutoff valve in the water supply line to the ice maker. See figure 1.
- Place a shallow pan under the water solenoid valve.
- The inlet fitting should be removed from the water solenoid valve. Drain water from the supply line. See figure 1.
- Remove the plastic nut and water line from the outlet side of the water solenoid valve. DO NOT LOSE METAL INSERT FROM PLASTIC WATER LINE! Drain water from line. See figure 1.
- *Connect compressed air onto the inlet fitting of the water solenoid valve. See figure 1. Apply AC power to the solenoid valve by forcing the ice maker mold assembly through several harvest cycles. Remove the plastic cover from the mold assembly. The bail arm must be in the down ("ON") position. Start the harvest cycle with a flat blade screw driver inserted into the center of the small gear. Turn the gear counterclockwise, when the hold switch closes, the mold assembly will continue to operate through the harvest cycle. See figure 2. During the water fill sequence of the harvest cycle the compressed air will blow out the water trapped in the solenoid valve. Repeat the harvest cycle operation several times.
- Reconnect the inlet and outlet water lines on the water solenoid valve. Metal insert MUST be installed in plastic water line going to outlet side of water solenoid. Leave the water supply turned off. See figure 1.
- Dry out the ice maker mold assembly with a soft cloth. Place bail arm in the "UP/OFF" position.
*Note: Up to 20 PSIG air pressure can be used to clear the solenoid valve. AC power can be applied to the solenoid valve for a maximum of 20 seconds.