Diagnostics and Troubleshooting
130
UNT-SVX07E-EN
Wireless Zone Sensors (WZS)
The receiver for all models has four LEDs: LED1, LED2,
LED3, and LED5.
Figure 101
shows their locations.
Note:
To view LEDs on a flush mount receiver on a fan coil
unit, the front panel of the unit must be removed.
The sensor for a wireless zone sensor (WZS) has four
LEDs: LED1, LED2, LED3, and LED5 and a test button.
Figure 102
shows their locations.
Wet interior
Coil face velocity too high
Reduce fan speed
Improper trap design
Design trap per unit installation instructions
Drain pan leaks/overflows
Repair leaks
Condensation on surfaces
Insulate surfaces
Excess dirt in unit
Missing filters
Replace filters
Filter bypass
Reduce filter bypass by ensuring all blockoffs are in place.
Microbial growth
(mold) inside air
handler
Standing water in drain pan
See “Standing water in drain pan” above
Table 63. Fan coil and cabinet heater troubleshooting recommendations
Symptom
Probable Cause
Recommended Action
Figure 101. Receiver for all fan coil models showing LED
locations
HEATING SET
FAN/SYSTEM
SETPOINT
ZONE
GND-SIGNAL
24VAC/DC
GND-POWER
COMM +
COMM -
S5
POWER
LED5
LED1
LED2
LED3
SIGNAL
ADDRESS
S1
S2
S3
J1
C33
S4
LED4
WIRELESS
INSTALL
J2
1
C34
C35
R77
Pb-FREE
LED1
LED2
LED3
LED5
Figure 102. WZS showing LED locations and test button
LED1
LED2
LED3
LED5
LED1
LED2
LED3
SIGNAL
LED5
WIRELESS
INSTALL
BATTERY
STATUS
B1 +
ADDRESS
S1
S2
S3
Pb-FREE
STATUS
S4
J1
B2 -
LED4
Test button
