9
Rev. D 1-19-00
P/N 471243
Proper Electrode Location
Proper location of the ignition electrode assembly is
important for optimum and safe system performance.
The electrode assembly should be located as noted in
Figure 6. The electrode assembly is NOT field
repairable and must be replaced if damaged.
Service Checks
Symptom
Cause/Cure
1. Dead
A. Miswired
B. Transformer bad
C. Fuse/circuit breaker open
D. Bad control (check LED for steady on)
2. Thermostat on,
A. Miswired
no spark
B. Bad thermostat no voltage @
terminal TH
3. Valve on, no spark
A. Shorted Ign. electrode
B. Open HV Ign cable
C. Miswired
D. Bad DSI control
4. Spark on, no valve A. Valve coil open
B. Open valve wire
C. Bad control (also check voltage
between V1 & V2)
5. Flame okay during A. Bad electrode
TFI, no flame sense B. Bad S1 or HV wire
(after TFI)
C. Poor ground at burner
D. Poor flame (check flame sensor
current, which follows)
Operation - Heater (contd.)
Flame Sensor Current Check
Flame current is the current which passes through
the flame sensor to ground. The minimum flame
current necessary to keep system from lockout is 0.7
microamperes. To measure flame current, connect
DC microammeter to the FC- FC+ terminals as
shown in Figure 7. The meter should read 0.7
microamperes or higher when the heater is firing.
Figure 6.
Figure 7.
