Wait 30 | Pilot | |
seconds | ||
light? | ||
(prepurge) | ||
| ||
| N |
24 volts
between 24V Y and
24V (GND) on ign. module?
N
Y | Main | Y | Do burners shut | Y |
down before | ||||
| burners |
| gauge temp |
|
| light? |
|
| |
|
| exceeds high limit |
| |
|
|
|
| |
| N |
| setting +15F? |
|
|
|
|
| |
|
|
| N |
|
See | "Intermittent |
|
|
|
Ignition System |
|
|
| |
Troubleshooting |
|
|
| |
Chart" on page 64 |
|
|
| |
|
|
|
| END |
*Defective L4080D
*Sensing bulb not bottomed out in well
*Loose harness 
*Defective CB502 board
*Loose, leaking, blocked, or reversed pressure switch tubes
*Leaks in flue collector joints *Foreign object in fan or flue collector
*Blockage in venting system
*Vent system not installed in accordance with installation manual
* Excessive silicone on I.D. of vent system joints
*Damaged or missing fan gasket
*Defective fan
*Wind at horizontal vent terminal in excess of 40 mph
*Incorrect fan outlet orifice
Do burner,
circulator and Y fan shut down at
end of call for
heat?
N
Does boiler shut | N | |
down when t'stat | ||
| ||
wire is removed from |
| |
t'sat terminal |
|
Y
*T'stat or zone system calling for heat
*T'stat wires shorted
*Internal boiler wiring problem, consult Crown representative
TROUBLESHOOTING CHART FOR BOILERS WITH CB502 CONTROL SYSTEM (USING
61
