Dometic MCS T6 Operating Manual page 31

MCS T6, MCS T12, MCS T16
Problem
System runs
continuously.
"ASF" (Air Sensor Fail-
ure) is displayed.
"FIL" (Filter Replace-
ment) is flashing.
"HPF" (High Freon Pres-
sure) is displayed.
EN
Possible Reason
Improper air sensor location.
Unrealistic set point.
Indicates failed face plate air sensor,
alternate air sensor or display cable.
Damaged jack/socket in display
head or on circuit board.
Filter needs replacement.
High-pressure switch is open (in
cooling) due to improper seawater
flow.
Strainer or intake may be plugged,
seacock may be closed.
High-pressure switch open (in heat-
ing) due to improper airflow.
Troubleshooting
Solution
Verify display head location.
Install alternate air sensor if
necessary.
Adjust set point until unit cycles off.
Unplug alternate air sensor if
installed or plug in alternate air sen-
sor if not installed.
Try another display cable.
Visually check to see that pins inside
socket are not bent or corroded.
Repair or replace display or circuit
board if needed.
Replace filter.
Reset P-21 to "00".
Check seawater hose for kinks or col-
lapses.
Verify pump operation.
Check pump circuit breaker if appli-
cable.
Remove obstructions in return air
stream.
Clean air filter and grille.
Check for crushed or restricted duct-
ing (ducting must be as straight,
smooth and taut as possible).
If problem persists,
– reprogram Low Fan Speed Limit
for maximum value: Set P-3 to
"64"
– set the reverse fan speeds during
Heating Mode parameter P-13 to
"rEF", or manually set fan speed to
high
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