Model HHC-990
303
4-7
5-2. ERROR CODES AND
The display shows the following error codes and warnings when a
WARNINGS
fault is detected, along with an alarm sound. Both the heat and
humidity systems shut down, except when specified otherwise.
Display
Cause
Panel Board Correction
“E-4
CPU TOO HOT”
• Control board too hot;
unit overheating or
louvers clogged
“E-5
AIR TEMP TOO HOT”
• Faulty relay, PC board,
or air probe
“E-54A CPU TEMP SENSOR
• Faulty PC board
OPEN”
“E-54B CPU TEMP SENSOR
• Faulty PC board
SHORTED”
“E-6A
AIR TEMP SENSOR
• Faulty air probe
FAILED OPEN”
• Turn switch to OFF position, then back to
ON; if display still shows “E-4”, the PC
board is getting too hot; clean louvers and
check cooling fan; if cooling fan is not
working, have it replaced; once panel
cools down, the controls should return to
normal; if “E-4” persists, have the PC
board replaced
• Turn switch to OFF position, then back to
ON; if display shows “E-5”, the heating
circuits and temperature probe should be
checked; once the unit cools down, the
controls should return to normal; if “E-5”
persists, have the PC board replaced
• Turn switch to OFF position, then back to
ON; if display shows “E-54A”, the
control should be re-initialized (see Pro-
gramming Section); if the error code
persists, have PC board replaced
• Turn switch to OFF position, then back to
ON; if display shows “E-54B”, the
control should be re-initialized (see Pro-
gramming Section); if the error code
persists, have PC board replaced
• Turn switch to OFF position, then back to
ON; if the display shows “E-6”, the
temperature probe should be checked;
once the temperature probe is repaired, or
replaced, the controls should return to
normal; if “E-6” persists, have the PC
board replaced
