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ELECTRONIC BOARD DIAGNOSIS/TEST
Each unit
has two ‘built-in’ tools to assist the technician in the troubleshooting of the entire system. The
first tool is the ‘Continuous System Diagnostics’, and the second tool is the ‘Automatic System
Component Test
’.
1- Continuous System Diagnostics: (Base or Intellitemp)
The control incorporates continuous self-diagnostic checking of several system parameters and reports
the status by an LED blink code on the main board.
1- Unplug or disconnect the power to the unit.
2- Gain access into the electric box on the chassis and locate the main board within.
3-
Locate the LED labeled ‘DIAGNOSTIC STATUS’ on the main board, near the center of the board.
4- Reapply power to the unit, wait approximately 10 seconds, after which the unit will enter its normal
operating mode. At
this time the diagnostic indicator LED will blink repeatedly. These ‘blink codes’
will repeat approximately every 5 seconds with a delay between bursts and are readable as follows:
a. 0 blinks = no power
b. 1 blink = normal
c. 2 blinks = IAT (indoor air temperature) probe failure (check connection
– replace)
d. 3 blinks = OAT (outdoor air temperature) probe failure (check connection
– replace)
e. 4 blinks = Between board communications failure
f. 5 blinks = Keypad failure (stuck key) or interconnect & ribbon cable failure
g. 6 blinks = Remote thermostat input failure (bad input combination) check thermostat wiring
h. 7 blinks = Inadequate ground
i.
8 blinks = Outdoor coil low temperature switch open (only if Heat Pump configured by DIP switch)
– Disables compressor operation
Summary of Contents for EZ Series 25
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