Troubleshooting
CLCH-SVX08C-EN
33
Unit will not run, locks
out on flame failure;
“Alarm” LED
illuminated on flame
relay panel.
Flame sensor not sensing pilot
flame
The manual gas valve may be closed; open it.
(3:1 and 10:1 turndown burners) UV flame sensor may be dirty; check the lens for dirt,
soot, and so on, and clean the lens, if necessary.
Check the ignition cable and wiring for loose, frayed connections or broken wiring. Repair
as necessary.
Pilot solenoid valve may not be opening.
Check for voltage at the pilot solenoid valve.
Check for sufficient gas pressure in the pilot line and adjust the pilot pressure regulator.
(20:1 Turndown Burners) Check flame rod for cleanliness, adequate grounding and that
it is properly located in the flame. Also ensure that temperature at flame rod insulator
is no greater than 500 F (260 C).
Perform Ignition Interference Test per component manufacturers manual.
Low flame signal voltage
Check flame signal voltage per procedure in Start-Up section.
(3:1 and 10:1 turndown burners) UV flame sensor may be dirty; check lens for dirt, soot,
and so on and clean the lens, if necessary.
The flame sensor may be defective; replace it.
(20:1 turndown burners) Check flame rod for cleanliness, adequate grounding and that
it is properly located in the flame. Also ensure that temperature at flame rod insulator
is no greater than 500 F (260 C).
CO is above 400 ppm. Gas pressure not adjust properly. Adjust gas pressure. See
Table 11. Troubleshooting gas heat sections (continued)
Symptom
Probable Cause
Recommended Action
