Filter
Top Products
4, Action: Established flame fails
Response:
• Burner motor is de-energized and oil primary con-
trol goes into recycle mode,
• If the fan off delay is longer than the recycle timing,
the heat fan continues to run through the next trial
for ignition.
5. Action: Limit Switch Opens
Response:
• Oil primary control shut off the burner.
• Circulating fan is energized immediately at cool
speed.
• A15 control board opens oil primary control T-3T
connections,
• Circulating fan runs as long as limit stays open,
6, Action: Limit Switch Closes
Response: If there is a heat demand, A15 control
board energizes oil primary control, initiating burner
light off.
Burner failure or improper operation can result from a num-
ber of different causes. Often the cause can be pinpointed
by observing the different types of failure or by the process
of elimination. The following troubleshooting charts list
some failures, causes and a sequence of steps to isolate
the point of failure. Check the simplest and most obvious
items before progressing to other items.
Source
Thermostat
Safety
Overloads
Power
Thermostat
CAD Cell
Primary Control
Procedure
Check thermostat settings.
Check burner motor,
primary safety control, &
auxiliary limit switch.
Check furnace disconnect
switch & main disconnect.
Touch jumper wire across
thermostat terminals on
primary control. Ifburner
starts, then fault is in the
thermostat circuit.
Disconnect the flame
detector wires at the
primary control. If the
burner starts, fault is in the
detector circuit.
Place trouble light between
the black and white leads.
No light indicates that no
power is going to the
control.
Place trouble light between
the orange and white leads.
No light indicates faulty
control.
Causes
Thermostat in OFF or
COOL
Thermostat is set too low
Burner motor overload
tripped
Primary control tripped on
safety
Auxiliary limit switch tripped
on safety
Open switch
Blown fuse or tripped circuit
breaker
Broken or loose thermostat
wires
Loose thermostat screw
connection
Dirty thermostat contacts
Thermostat not level
Faulty thermostat
Flame detector leads are
shorted
Flame detector exposed to
light
short circuit in the flame
detector
Primary or auxiliary control
switch is open
Open circuit between
disconnect switch and limit
control
Low line voltage or power
failure
Defective internal control
circuit
Correction
Switch to HEAT.
Turn thermostat to higher temperature.
Push reset button pump motor.
Reset primary control.
Reset auxiliary limit.
Close switch.
Replace fuse or reset circuit breaker.
Repair or replace wires.
Tighten connection.
Clean contacts.
Level thermostat.
Replace thermostat.
Separate leads.
Seal off false source of light.
Replace detector.
Check adjustment. Set the maximum setting.
Jumper terminals; if burner starts, switch is faulty,
replace control.
Trace wiring and repair or replace it.
Call the power company.
Replace the control.
table continued on next page
Page 19
O23V SERIES