106636-02 - 12/19
23
X-2
Installation, Operating & Service Manual
10
Operation
Status Codes displayed in
STA
Mode
Status
STA
Description
Standby
(Burner off
Circulator off)
1
No call for heat detected
Circulator
Pre-purge
(burner off
circulator on)
1
Either condition is true:
a. Call for heat detected and boiler
temperature higher than operating
setpoint.
b. Call for heat detected and boiler
temperature higher than Start
Temperature (140°F default) and
Circulator Pre-purge Time has not
expired.
Self Test
17
Control internal checking
Drive Damper
Open
18
Damper is energized. Control is
waiting for damper switch to close.
If damper end switch doesn't close
within 60 seconds, control goes to
STA
20
Pre-purge
4
Damper is open for a 2 second delay
Spark
6
Pilot fuel valve is open and sparking
has started.
Flame
Proving
7
Main fuel valve is open and flame is
being proven.
Running
8
Burner runs until call for heat is
satisfied or operating setpoint is
reached.
Table 10-1: Sequence of Operation
Status Codes displayed in
STA
Mode
Status
STA
Description
Retry /
Recycle
Delay
10
If burner fails to light off (no flame
signal), it waits 5 minutes and retries
or if control loses flame signal during
running, it will wait 10 seconds and
then recycle.
Soft Lockout
13
System is shut down and will restart
following a one hour enforced delay.
Hard Lockout
14
System is locked out. A manual or
power reset is required to light off
again.
Limit Open
15
There is a call for heat from
thermostat, but Limit is open.
Flame
Present Out
of Sequence
16
Flame signal is still present when
expected to be 0 (no flame).
Damper
Failed to
Open
20
Damper is still energized and damper
end switch has not closed.
Table 10-2: Sequence Fault
A. Boiler Sequence of Operation (See Table 10-1)
1. When thermostat calls for heat, control starts
system circulator.
2. If thermostat is not satisfied with residual
heat in boiler, or boiler water temperature is
less than start temperature (140oF) setpoint,
start sequence continues by energizing vent
damper. Once vent damper is fully open,
ignition sequence is started. Damper must be
in open position when appliance main burners
are operating.
3. If thermostat is not satisfied and operating set
point has been reached, system circulator
will continue to operate and burners will stop.
When boiler water temperature drops below
setpoint less differential setting, burners will
restart.
4. After thermostat is satisfied, burners and
circulator are stopped and vent damper is
closed.
5. When indirect water heater thermostat is wired
to DHW input, aquastat calls for heat and
control starts DHW circulator. Vent damper is
energized without delay and ignitor sequence
is started.
B. Boiler Fault
If boiler fails to start, control provides status
information to help determine cause of problem.
Table 10-2 provides a list of boiler status codes
that are reported.
C. Using Display
Control is located inside boiler front door.
The control display, along with Up
, Down
, and “
I
” keys
may be used to view boiler operating status (Figure 10-4).
