Table of Contents
Advertisement
9. If ignition system fails to operate properly,
repair work must be performed by a qualif ied
serviceman or installer.
HOT SURFACE IGNITION SYSTEM
Hot Surface Ignition
Control Module
300,000 Btu/hr models &
FIG. 37
Service Parts
This unit uses a proven pilot electronic hot surface ignition
control module and a hot surface igniter. The hot surface
ignition module is not repairable. Any modification or
repairs will invalidate the warranty and may create
hazardous conditions that result in property damage,
personal injury, fire, explosion and/or toxic gases. A faulty
hot surface igniter or ignition module MUST be replaced
with a new OEM unit only. An OEM specification igniter
and ignition control module for this specific unit is
available from your local distributor.
general purpose field replacement ignition modules or
igniters.
Hot Surface Igniter
Hot Surface Igniter and Ignition Module
The 300,000 Btu/hr models have one ignition module and one
hot surface igniter. The 990,000 through 2,070,000 Btu/hr
models have two ignition modules and two hot surface igniters.
990,000-2,070,000
models reset
DO NOT use
FIG. 38
HOT SURFACE IGNITION CONTROL MODULE
Ignition Module Lockout Functions
The ignition module(s) may lockout in either a hard
lockout condition requiring pushing of the reset button to
recycle the control or a soft lockout condition which may
recycle in a fixed time period to check for correction of
the fault condition. A typical hard lockout fault is a flame
failure condition. An ignition module that is in a hard
lockout condition may only be reset by pushing the reset
button for the ignition control. The reset button is located
inside front control panel on the side of the ignition
module. The reset button is active after the post purge
cycle when there is hard lockout condition as indicated
by the Status LED. Turning main power "OFF" and then
"ON" or cycling the thermostat will not reset a hard
lockout condition. Wait five seconds after turning on main
power before pushing the reset button when the ignition
module is in a hard lockout. The ignition module will go
into a soft lockout in conditions of low air, low voltage or
low hot surface igniter current. A soft lockout condition
will operate the combustion air fan for the post purge cycle
and then the ignition module will pause for a fixed time
period. The timed length of the pause is based on the type
of fault sensed by the control module. At the end of this
timed pause, the ignition module will attempt a new trial
for ignition sequence. If the soft lockout fault condition
has subsided or has been corrected at the end of the timed
pause, main burner ignition should be achieved with the
resumption of the normal trial for ignition sequence. If
the control sensed fault is not corrected, the ignition
module will continue in the soft lockout condition. If the
electronic thermostat opens during the soft lockout period,
the ignition module will exit soft lockout and wait for a
new call for heat from the thermostat. A soft lockout
condition may also be reset by manually cycling the
electronic thermostat or turning the main power switch
"OFF" and then "ON" after the control sensed fault has
been corrected.
Diagnostic Status Indication
The ignition module has an LED which indicates the status
of the safety circuits. A remote Ignition Module Status
indicating light(s) is wired from the ignition module Status
LED and mounted on the front control panel (990,000
through 2,070,000 Btu/hr models). The flashing operation
of this light/LED indicates the diagnostic status of the
ignition control module. The status LED, mounted on the
ignition module, flashes a code sequence from the Ignition
Module to indicate the status of the ignition process. The
following listing gives the flashing diagnostic status codes
as signaled by the ignition module.
36
Advertisement
Table of Contents
