Dunkirk Excelsior EXB Series - Manual (Page 15)

15
Beckett NX BURNER TROUBLESHOOTING
Condition 1: Burner motor does not start when there is a call for heat.
Procedure Status Corrective Action
N/A N/A
N/A N/A
Green Indicator light
is on.
Cad cell is defective, sees external light, or connections have shorted. Go to step
4.
Green Indicator light
is off.
Go to step 6.
Green Indicator light
turns off.
Eliminate external light source or permanently shield cad cell.
Green Indicator light
stays on.
Replace cad cell with new cad cell and recheck.
If indicator light does not turn off, remove cad cell lead wires from Aquastat and
recheck.
If indicator light is still on, replace the Aquastat control.
If the indicator light turns off, replace cad cell bracket assembly.
Green Indicator light
is on.
If fl ame is present, replace the oil valve.
IMPORTANT
First remove one thermostat lead wire.
Burner starts.
Trouble is in thermostat circuit. Check thermostat-wiring connections.
If connections are clean and tight, check thermostat wires for continuity.
Burner does not start.
• Disconnect line voltage power and open line switch.
• Check all wiring connections.
• Tighten any loose connections and recheck.
• If burner still doesn’t start, replace Aquastat.
If burner still doesn’t start, check the oil burner motor. It may be seized or
burned out.
OPERATION AND TROUBLESHOOTING