71
SSCBL-RPBL-IOM (10-22) 149159-C
Spark Ignition System Maintenance
⚠ WARNING ⚠
Due to high voltage on pilot spark wire and pilot electrode, do not touch when energized.
NOTE: When checking for spark with the pilot burner assembly removed from the burner rack, the
pilot assembly must be grounded to the heater for proper spark.
1 . If no spark occurs, check the following:
a . Using microampmeter, measure voltage between terminals TH and 7 on ignition controller . Voltage should
be at least 20V and no higher than 32V . Refer to
section if no voltage is observed .
b . Check for short to ground in high tension lead and/or ceramic insulator .
c . Verify that pilot spark gap (see
) is approximately 7/64 inch for RPBL models or 0 .100 inch for
SSCBL models .
d . If the above conditions are normal and no spark occurs, replace the ignition controller .
NOTE: If replacing an earlier model of ignition controller (see
, order a replacement kit
(PN 257472 for a unit with recycling gas control option AH2 or PN 257473 for a unit with gas control
with lockout option AH3). Option codes are listed on the unit wiring diagram.
Figure 51. Obsolete Ignition Controllers
2 . If the main gas valve fails to open with a normal full-size pilot flame established, check the following:
a . If voltage between black and brown leads on main gas valve is 20–32 VAC and there is no main gas flow with
built-in manual valve in FULL OPEN position, main valve is defective .
b . If there is no voltage between black and brown leads on main gas valve, check for disconnected or shorted
flame sensor lead or flame sensor probe .
3 . If the above conditions are normal and main gas flow is still off, the ignition controller is probably defective . Do
not attempt to service the ignition controller as it does not contain any replaceable components .
IGNITION CONTROLLER WITH
LOCKOUT FOR GAS CONTROL
OPTION AH3, UTEC MODEL 1003-514
(PN 257010): REPLACE WITH
REPLACEMENT KIT (PN 257473)
RECYCLING IGNITION CONTROLLER
FOR GAS CONTROL OPTION AH2,
UTEC MODEL 1003-638A
(PN 257009): REPLACE WITH
REPLACEMENT KIT (PN 257472)
