Specifications

MODBUS COMMUNICATION MANUAL
A-2
Table A-1. Status and Fault Messages
Code MESSAGE DESCRIPTION
1 DISABLED
HH:MM pm MM/DD/YY
Displayed if ON/OFF switch is set to OFF. The display
also shows the time and date that the unit was disabled.
2 STANDBY
Displayed when ON/OFF switch is in the ON position, but
there is no demand for heat. The time and date are also
displayed.
3 DEMAND DELAY
XX sec
Displayed if Demand Delay is active.
4 PURGING
XX sec
Displayed during the purge cycle during startup. The
duration of the purge cycle counts up in seconds.
5 IGNITION TRIAL
XX sec
Displayed during ignition trial of startup sequence. The
duration of cycle counts up in seconds.
6 FLAME PROVEN
Displayed after flame has been detected for a period of 2
seconds. Initially, the flame strength is shown in %. After
5 seconds has elapsed, the time and date are shown in
place of flame strength.
7 WARMUP
XX sec
Displayed for 2 minutes during the initial warm-up only.
8 HIGH WATER TEMP
SWITCH OPEN
The High Water Temperature Limit Switch is open.
9 LOW WATER
LEVEL
The Water Level Control board is indicating low water level.
10 LOW GAS
PRESSURE
The Low Gas Pressure Limit Switch is open.
11 HIGH GAS
PRESSURE
The High Gas Pressure Limit Switch is open.
12 INTERLOCK
OPEN
The Remote Interlock is open.
13 DELAYED
INTERLOCK OPEN
The Delayed Interlock is open.
14 AIRFLOW FAULT
DURING PURGE
The Blower Proof Switch opened during purge.
15 SSOV FAULT
DURING PURGE
The SSOV switch opened during purge.
16 PRG SWTCH OPEN
DURING PURGE
The Purge Position Limit switch on the Air/Fuel valve opened
during purge.