HydroTherm HeatNet KN -6 User Information page 106

APPENDIX B
Line # 4 Message
HIGH DELTA TEMP
SHUTDOWN UV TEST
HIGH LIMIT EXCEEDED
IGNITION CTRL ALARM
IRI Alarm
DOMESTIC HOT WATER
LOW WATER CUTOFF
VAR FREQ DRIVE
GAS PRESSURE
SPARE 4
OP LIMIT MECH
START FAILED, RETRY
OP LIMIT REMOTE
OPEN OUTSIDE SENSOR,
SUPPLY SENSOR,
RETURN SENSOR,
HEADER SENSOR,
DHW SENSOR
SHORTED OUTSIDE SENSOR,
SUPPLY SENSOR,
RETURN SENSOR,
Description
This log entry occurs when the temperature across the heat exchanger has
been greater than the EXCHR DELTA T RANGE degrees F.
After 24 hours of continuous runtime the ignition control module needs to
check it's UV detection circuit. An orderly shutdown and then a restart will
occur. This log entry indicates that this has taken place. This is not a fault.
If the mechanical aguastat trips due to it's high temperature setting having
been exceeded, this log entry will occur.
The ignition control module has faulted while performing an ignition
sequence, or while monitoring flame during normal operation.
If the gas valve proving circuit ( if equipped) detects a gas pressure problem.
Indicates a call for DHW heating by either the DHW sensor or an external
thermostat.
These log entry faults are result of the interlocks connected to the 24VAC
interlock inputs: J11A and J11B.
Low Water Cutoff = Low water condition in boiler
Var Freq Drive = The blowers Variable Frequency Drive has a problem
Spare 4 = User installed interlock,
Op Lim Mech = An external operator (aquastat).
If the H-Net control closes the last interlock string entering the ignition
control and the ignition control never closes its Blower Relay, the H-Net
control will wait 2 minutes. The H-Net control will then retry for the duration
of the local pump post purge time and then retry the ignition sequence. During
this time ―retry strt‖ will be displayed in the status screen. After (5) attempts
the H-Net control will lock out and display call service. The Log will report
the retries.
The is the firmware Operating Limit as defined in
SETUP:SETPOINTS:OPERATE LIM. When the Supply temperature exceeds
this value, this event is logged.
If one of the 10k thermistor sensors was detected to be open or not connected,
this fault will be logged.
If one of the 10k thermistor sensors was detected to be shorted this fault will
be logged.
HeatNet V3 2.x
Page 106