Section V: Troubleshooting
•the igniter continues to glow red
after the pilot is lit, or
•the pilot lights and the igniter stops
glowing red, but the main burner
does not light.
If so, assure adequate flame current
as follows:
•turn off the appliance at the circuit
breaker or fuse box
•clean the flame rod with an emery
cloth
•make sure electrical connections are
clean and tight.
•check for a cracked ceramic insula-
tor, which can cause short to ground,
and relace the igniter-flame rod as-
sembly if necessary (see instructions
later in this section).
Turn on the power and set the
thermostat to call for heat. The pilot
should light and then the main burn-
er should light.
Fig. 5.2: The SV9501/9502 SmartValve™ Troubleshooting
Sequence
Turn gas supply off
Set thermostat to call
for heat
No
Check:
Line Voltage Power
Low Voltage Tranformer
SV9500 is powered
(24 VAC is nominal)
Limit Controller
Thermostat
Wiring
Igniter warms up and
glows red
Pilot valve opens
No
Unplug pilot burner cable,
Measure voltage at SV9500
HIS terminals (24 VAC
nominal)
No
Replace SV9500 Smartvalve
Yes
Replace igniter / sensor
assembly
Turn gas on
Pilot burner lights
No
Measure voltage to SV9500
Voltage must be at least
19.5 VAC.
No
Check transformer line volt
supply
Yes
Yes
Main valve opens
No
Replace igniter / sensor
assembly
and
retain.
Restart
troubleshooting
se uenc e. oes main valve
open
No
Replace SV9500 Smartvalve.
Save old igniter / sensor
assembly for service.
Yes
Yes
System
iscar d old igniter / sensor
assembly
Checking the Grounding
1. If the ground is poor or erratic, safety shutdown will
occur. Therefore, if nuisance shutdowns are reported,
check that the ground is made through the pilot tubing.
2. Excessive temperature at the ceramic flame rod
insulator will permit electrical leakage to ground.
• If the bracket is bent, bend it back to the correct position.
• If the insulator is cracked, replace the igniter-flame rod
assembly (Q3400A).
Checking the Ignition Cable
1. Make sure that the ignition cable is not in contact with
metal surfaces.
2. Make sure the ignition cable is not more than 3 ft. (or 1
m.) long.
3. Check the electrical continuity of the ignition cable.
Checking and Adjusting Gas Input and Burner Ignition
Proper gas pressure is necessary for proper operation of
the equipment. Check the inlet and outlet pressure of the
gas control valve using the procedure described in item
6 of Section I: Installation, entitled Pressure Testing Gas
Lines.
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