GE AZ45E07EA Series Technical Service Manual page 51

Fault Code Fault Meaning
Number
F19* Make-up Air Module Outdoor
Thermistor Fault
The MUAM outdoor thermistor is
not reading valid temperatures
(the thermistor is not plugged in
or is shorted resulting in out of
bound ADC readings). This fault
is never cleared.
20* Make-up Air Module Indoor Coil
Thermistor Fault
The MUAM indoor coil thermistor
is not reading valid temperatures
(the thermistor is not plugged in
or is shorted resulting in out of
bound ADC readings). This fault
is never cleared.
21* Make-up Air Module Humidity
Thermistor Fault
The MUAM Humidity thermistor
is either reading invalid relative
humidity, or invalid temperature.
This fault is never cleared.
22* Make-up Air Module Coil Frost
If the coil temperature drops
below 34° F, the coil frost fault
is set. Once the temperature
rises above 50° F, the fault will
be cleared. When the fault is set,
* Future fault codes
is ACTIVE
by MUAM.
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Fault reset
time