Aprilaire 1710A - Blinks

7 | P a g e
Old or New Control with Internal Control, or Model 76 Remote Control
- The blower will come for 3 minutes to sample the incoming air. If the inlet air is
above 105° the blower will shut off and the 5 flash error code will be displayed. At
the start the next cycle period the fault will end and the air will be sampled again.
- If the inlet temperature remains above 105° after 3 minutes of dehumidifier blower
run time, check for duct leakage on the inlet side and duct blockage on the outlet
side.
 Basement installations – Low temperature may be offset by mixing air from the home
into the dehumidifier.
 Crawlspace space applications – The dehumidifier will correct itself when the low
temperature conditions stop.
 Ventilation applications – High or low temperatures may be offset by mixing air from the
home into the dehumidifier.
6 blinks The signal from the Frost Sensor is out of the allowable range (-20°F to 150°F). The most
likely reason for this fault is a poor connection at the control board or a damaged sensor.
1. Check the Frost Sensor connections at the control board. Tug on the wires to verify that
the quick connect terminals connection to the wires are not loose.
2. Remove the front panel and inspect the sensor. If it looks crushed or damaged, replace
the sensor.
3. With the ON/OFF switch ON and the control knob set to OFF, measure the voltage at the
frost sensor terminals. Do not disconnect the wires from the terminals when reading the
voltage (see page 5). The voltage should correspond approximately to room temperature
in accordance with the tables on page 5.
7 blinks The Float Switch input to the control board is open. This will occur if there is a float switch
installed, and there is sufficient water in the secondary drain pan to cause the float switch to
open, or if the installed float switch is faulty or not the appropriate type (must be a normally
open switch that is not powered). If a float switch is not installed, the jumper in the Float
Switch terminals is missing or not properly seated.
1. Leave the unit ON with the fault code blinking. It will stop blinking without having to turn
the unit OFF to reset when the fault has been repaired.
2. Drain the water out of the drain pan.
3. Remove the Float Switch terminal block from the control board and inspect the terminal
block to ensure the wires are properly seated. If a float switch is installed, do a
continuity check between the float switch terminals – there should be continuity.
Replace the float switch if needed.