Troubleshooting - Zehnder Rittling VS Series Installation, Operation And Maintenance Manual

Troubleshooting

Error Code
Fault Description
(commtstat)
High pressure lockout
> 600 psig
Low pressure lockout
< 40 psig
Freeze protection
H O side
2
Freeze protection
air side < 35 °F
Condensate overflow ER 9, ER 10
Over/under low
voltage protection,
18 VAC > voltage < 30VAC
LWT sensor failure
(low water temperature)
DAT sensor failure
(discharge air temperature)
FP1 sensor failure
(freeze protection)
FP2 sensor failure
(freeze protection)
Table G: Technical Diagnosis
System Warning (Flash)
LD1 LD2 LD3
ER 1 Off Off Off
ER 2 Off Off Flash
ER 4 Off Off Flash
ER 5 Off Flash Off
Off Flash Off
ER 11 Off Flash Flash
ER 13 Flash Off Off
ER 14 Flash Off Off
ER 15 Flash Off Flash
ER 16 Flash Off Flash
System Lockout (Steady On)
LD4 LD1 LD2 LD3
Flash Off Off Off
Off Off Off On
Flash Off Off On
Off Off On Off
Flash Off On Off
Flash Off On On
Off N/a N/a N/a
Flash N/a N/a N/a
Off On Off On
Flash On Off On
Possible Fault Cause
LD4
Low air flow (heating)
On
Low water flow (cooling)
Off Low refrigerant charge
Water temperature
On
< 35 °F or < 15 °F (heating)
Off Blower failure (cooling)
On Clogged drain line
On Loss of power, brown out
Sensor resistance above
N/a
or below specification
Sensor resistance above
N/a
or below specification
Sensor resistance above
Off
or below specification
Sensor resistance above
On
or below specification
Troubleshooting 57