Troubleshooting the Oil Burner Primary Control

Table 5-4 lists possible remedies to a number of different operating problems associated with oil burner primary controls. Before checking the primary control, examine the following parts of the oil burner and ignition systems:

• Main power supply and burner motor fuse
• Ignition transformer
• Electrode gap and position
• Contacts between ignition transformer and electrode

Other system components that should be checked before examining the primary control are the oil piping to the tank, the oil filter, oil pump pressure, oil nozzle, and oil supply.

Table 5-4 Troubleshooting Oil Burner Primary Control

Symptom and Possible Cause Possible Remedy
Repeated safety shutdown.
(a) Slow combustion thermostat response. (a) Move combustion thermostat to better location. Adjust for moreefficient burner flame. Clean surface of cad cell.
(b) Low line voltage. (b) Check wiring and rewire if necessary. Contact local power company.
(c) High resistance in combustion thermostat circuit. (c) Replace combustion thermostat.
(d) High resistance in thermostat or operating control circuit. (d) Check circuit and correct cause.
(e) Short cycling of burner. (e) Clean filters. Reset or replace differential of auxiliary controls. Repair or replace faulty auxiliary control. Set thermostat heat anticipation at higher amp value. Clean holding circuit contacts.
(f) Short circuit in combustion thermostat cable. (f) Repair cable or replace combustion thermostat.
Relay will not pull in.
(a) No power; open power circuit. (a) Repair, replace, or reset fuses, line switch, limit control, auxiliary controls.
(b) Open thermostat circuit. (b)With power to relay, momentarily short thermostat terminals on relay. If burner starts, check wiring.
(c) Combustion thermostat open. (c) Repair or replace combustion thermostat.
(d) Ignition timer contacts open. (d) Clean magnet.
(e) Open circuit in relay coil. (e) Replace relay.

3 Replies to “Troubleshooting the Oil Burner Primary Control”

  1. Oil burner will not shut off. Tried replacing Honeywell triple aquastat, burner still continues to run past the 180 degree high limit setting causing pressure relief valve to release. Burner does not shut off until emergency switch is turned off.

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