36
P/N
240011589
, Rev. A [08/03/2016]
Table 9 - Induced Draft Models State Codes
1. State code sequence through a normal heat cycle.
Order
State
code
Definition
Explanation
a
1
Idle
There is no call for heat; and/or:
b
1
Circulator
Thermostat has called for heat. Control activated system circulator pump and is waiting
to see if there is enough heat stored in the boiler to satisfy the t'stat without firing the
burners. This may last as long as 2 minutes, but will typically be much less.
c
17
Diagnostics
Pilot valve diagnostics/current leakage detection. Typically a few seconds.
d
2
Wait for pressure switch to open
Inducer motor should be off while boiler is off to conserve energy. Control is verifying
motor is acutally offr (switch must be open).
e
3
Wait for pressure switch to close
Control starts inducer (vent motor). A pressure switch must close to verify motor
is operating and vent to outside is not obstructed. If this does not occur after one
minute, control will go into ERR29. Should the switch eventually close, control will
resume normal operation.
f
4
Pre purge
Control is clearing gases out of the heat exchanger. Also, internal electronic diagnostic
check is performed.
g
6
Spark
Spark for ignition. There should be audible sparking (buzzing) noise. This will last until
control detects pilot flame, but no more than 30 seconds. (If no flame is detected after
trial period, sparking will stop, and 5 minute delay will occur before control tries again.
STA10 will be displayed during this period).
h
7
Flame stabilization
Pilot flame must be strong enough (1 uA) for control to release main burners. This will
last up to 10 seconds. (If flame is still not strong enough after 10 seconds, control will
shut off the pilot, wait 5 minutes, then try again. STA10 will be displayed during this 5
minute period).
i
8
Running
Main burners are providing heat. This will continue as long as thermostat requires.
During this period, control will monitor pilot signal, boiler temperature, damper, and
limit switches to assure safe operation.
j
9
Post-purge
Inducer motor is purging gases after heat cycle.
k
1
Post operation.
Circulator pumps will continue for short time to deliver stored heat to house before it
has a chance to escape during coming off period.
2. Other possible state codes
j
10
Retry Recycle Delay
5 minute delay after pilot signal is lost. EITHER:
1. Control failed to detect pilot flame after spark period. Check pilot for contamination;
check ignition wire; check electrical ground; check pilot flame.
2. Control lost pilot flame signal AFTER main burners were lit. Check for adequate draft
and combustion air. Check gas line for adequate pressure.
k
11
Wait for pressure switch to open -
failed closed
Inducer is still off, but pressure switch has not opened at beginning of heat cycle.
Alarm is sent, but no lockout occurs.
l
12
Wait for pressure switch to close -
failed open
Inducer is on but pressure switch has not closed yet at beginning of heat cycle.
Alarm message is sent but no lockout occurs.
m
13
Soft lock out
Soft lockout duration is one hour, may override with manual reset. Appropriate error
code will flash alternately.
n
14
Hard lock out
Requires manual reset. Unacceptable high water temperature (err 65) and onboard
electronics failure (err 18) are the only hard lockouts on this model.
o
15
Wait for limit to close
One of the safety limits - rollout, or Low water cutoff (if one is field installed on 24V
safety circuit) has been activated. Control will resume normal operation once limit is
reset. Underlying cause why limit switch opened MUST be investigated.
p
16
Flame out of sequence
Flame signal sensed before trial for ignition. Appropriate alarm is sent.
OR
Flame signal sensed out of sequence during post purge
OR
Flame signal present when not expected. Appropriate alarm is sent.
q
17
Diagnostics
Onboard self check performed at various points during operation sequence.
APPENDIX A - CONTROL MODULE
