GE GEH50DEED Technical Service Manual page 12

Dry Tank Test
Upon initial installation, or anytime the power is off and power is then connected, the water heater will run a
dry tank test before starting the selected heating mode.
After approximately 2 minutes, the control will turn on the compressor and fan motor. The control will run
the sealed system for 5 minutes and monitor the tank temperature from the T2 sensor. if the control sees
a temperature rise of more than 3.5 degrees within the 5 minutes, it assumes the tank is empty, shuts off
heat, and displays an F11 fault code warning to fill the tank (a full tank would absorb the heat, and the
temperature increase would take longer).
Note: in the event of a power loss, when power is restored, the control will resume whatever heating mode
had been operating prior to power loss.
Sealed System Startup
The upper limit avoids a
compressor overheat, the lower
limit prevents liquid refrigerant
from entering the compressor
as well as inefficiency due to the
lack of heat in the air.
room temperature between
45°F and 120°F and
evaporator above 32°F?
Start sealed system.
Ensure compressor
has been off for at
least 2 minutes
Ambient
temperature OK?
45F< T5 >120F
Yes
Is evaporator
free of frost?
T3a >32F
Yes
Start Sealed System
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No
Switch to electric
element
No
Switch to electric
element
(Continued Next page)