Aprilaire 1150 - Manual (Page 8)

TABLE 2 – Display Panel Light Indications
Indicator light(s) Status Description
All
Blinking sequentially from
right to left
The humidifier is in a forced cool-down period prior to a required automatic drain sequence.
Normal operation
On/Off (switch)
On Power is on. Normal operation.
Slow blinking (1/sec.) The electronic water level probe needs cleaning.
Fast blinking (10/sec.) Probe logic fault. See Troubleshooting section.
Drain
On The humidifier is draining. Normal operation.
Blinking
The allowed amount of time for draining has been exceeded. Fault in drain operation.
Humidifier will continue to operate. See Troubleshooting section.
Fill
On The humidifier is filling. Normal operation.
Blinking
The allowed amount of time for filling has been exceeded. Fault in fill operation.
Humidifier will not operate. See Troubleshooting section.
Steam
On The humidifier is making steam. Normal operation.
Blinking
The humidifier has received a demand signal but cannot make steam because:
• There is not enough water in the chamber, or
• An enable/safety switch is open, or
Note:
See the Troubleshooting section in this manual for more information.
AUTODRAIN SEQUENCE MINIMIZES OUTPUT INTERRUPTIONS
The humidifier drains and flushes automatically at regular intervals to remove minerals from the chamber.
After the humidifier has run for a preprogrammed amount of time, and if there is no demand for humidity, the humidifier sits idle
until the chamber cools and then it drains.
If the humidifier has not completed an autodrain sequence due to continual demand signal interruptions, after an additional
amount of run time the humidifier begins a cool-down period and then it drains.
IMPORTANT: The humidifier attempts to complete an autodrain sequence when there is no demand for humidity. However,
if an autodrain sequence is not completed within a defined period of time, the humidifier ignores the demand signal until
completing an autodrain sequence. This could cause the relative humidity level in the humidified space to drop until the autodrain
sequence completes.
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