Aprilaire 1700 Not in direct sunlight, Verify that the Outdoor Temperature Sensor

TROUBLESHOOTING GUIDE (CONTINUED)

SYMPTOM TROUBLESHOOTING PROCEDURE / POSSIBLE REASON

The ventilation damper does not open when the HVAC fan is active.

•The damper will not open if the cycle time within the current period has already been met. For instance if the cycle time is set to 5 minutes and the control has already ventilated for 5 minutes in that interval, the damper will remain closed.

•If using the Outdoor Temperature Sensor, check that it is installed in the Outdoor Air Intake a maximum of 3 feet from the outside, or on the North, East or West side of the house.

(Not in direct sunlight.)

•If the outdoor temperature is below 0°F or above 100°F, the damper will remain closed.

•Verify that the Outdoor Temperature Sensor

is reporting an accurate resistance. Remove the Outdoor Temperature Sensor leads from ODT Sensor terminals and check the resistance. Compare the reading with the resistance shown in Table 2.

TABLE 2

Outdoor
Temperature	Resistance
-30˚F	229,500 OHMS
-20˚F	162,500 OHMS
-10˚F	116,500 OHMS
0˚F	84,500 OHMS
10˚F	62,000 OHMS
20˚F	46,000 OHMS
30˚F	34,500 OHMS
40˚F	26,000 OHMS
50˚F	20,000 OHMS
60˚F	15,500 OHMS
70˚F	12,000 OHMS
80˚F	9,500 OHMS
90˚F	7,500 OHMS
100˚F	6,000 OHMS

The fan turns on unexpectedly.

•The control will turn on the fan as needed to meet the air cycling requirements determined by the cycle time and cycle period settings.

The dehumidifier does not run.

•Follow all of the system checkout procedures.

•Check that the power switch on the dehumidifier is on.

•Check that the circuit breaker is not tripped. The dehumidifier requires a minimum of 8 amps. The dehumidifier should be placed on its own dedicated 15 amp circuit.

The compressor never runs.	• If a float switch is not installed, confirm that the jumper is installed at the
	float switch terminals on the control board.
	• If a float switch is installed, confirm that the float switch is not open.

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