– 23 –
Symptom
Cause
Remedy
1.
Slowly
open valve.
2. Increase gas pressure.
3. Clear obstruction in vent orifi ce/
line or replace if defective.
4. Check for correct installation and
voltage. Correct or replace.
5. Replace with factory required
type of gas.
6a. UV Sensor - clean lens and sight
tube and check wiring and spark
plug.
6b. Flame Rod - assure rod is in
fl ame, check wiring and fl ame
rod.
7. Check wiring or replace
transformer if correct.
1. Place in run position (see
technical cut sheet on fl ame
safeguard relay).
1. Disable the fan and heat.
Slowly
open all manual gas shut-off
valves before restarting.
2. Clear obstruction in vent orifi ce/
line or replace if defective.
3. Enable the fan and heat. After
10 seconds of prepurge, pilot will
light. Then after 10 seconds main
valve light will come on. Check to
see if all gas valves have opened.
If not, check voltage at gas valve.
If voltage is found to be correct,
replace gas valve or actuator
(see Section X on Maxitrol
troubleshooting Guide for
modulating valve).
4a. Check burner for low fi re
adjustment.
4b. UV Sensor - clean lens and sight
tube and check wiring.
4c. Flame Rod - be sure fl ame rod is
in main fl ame, check wiring and
fl ame rod.
5. Check for power and/or replace.
1. Manual pilot shut-off valve closed.
2. Inlet gas pressure lower than
required gas pressure
3. No gas through pilot regulator
with inlet gas pressure ok.
4. No gas through pilot solenoid.
5. Type of gas (natural - LP)
supplied different from factory
required type. Note: components
may change.
6. Flame detection system not
sparking or sensing pilot fl ame.
(See spark rod diagram in
Section IX.)
7. No voltage on secondary side of
ignition transformer.
1. Flame safeguard relay Run/
Test switch in Test position or
functioning problem.
1. Manual gas shut-off valve closed.
2. No gas on outlet side of
regualtors with inlet pressure ok.
3. No gas on outlet side of valve or
actuator with inlet pressure ok.
4. Main fl ame rod or scanner not
sensing main burner.
5. RE-75 energized
SECTION VII - TROUBLESHOOTING
continued
D. Pilot does not light after
prepurge has timed
out (10 seconds) and
voltage is present on
fl ame safeguard output
terminals.
E. Pilot does not light after
prepurge has timed out
and there is no voltage
at fl ame safeguard relay
output terminals.
F. No heat with pilot ok
and voltage is present
at fl ame safeguard relay
output terminals.
Heat Mode
continued
(Refer to Digital Control System User Manual for additional troubleshooting suggestions)
