Model DP Oil-Fired Heater
Page 17
2.
Replace the oil nozzle once a season (see the oil
burner Manual).
3.
Oil the burner motor every three months. Use
non- detergent #40 motor oil at both oil holes.
4.
Replace the in-line oil filter cartridge once a year.
SECTION 5.
Service Information
5A. Control and Cad Cell Tests
IMPORTANT: In the following test procedures:
1.
The 2,000 ohm resistor checks the calibration and
performance of the primary safety control.
2.
The ohm meter checks cad cell operation only.
Test Instructions
1.
Remove two thermostat wires from the primary
control.
2.
Push reset buttons on burner motor and primary
control.
3.
Remove two cad cell wires from primary control.
4.
Connect ohmmeter leads to cad cell wires.
5.
Set ohmmeter range to 1 KW.
6.
Connect resistor wires to cad cell terminals on the
Step 2. primary control.
7.
Place a jumper wire on the thermostat terminals
on the primary control.
8.
Loosen one cad cell terminal screw on the
primary control. Move the resistor wire slightly
to temporarily break contact. When the burner
starts, quickly tighten the terminal screw.
9.
Check combustion to make sure there is flame. If
there is no flame, open the thermostat jumper and
stop the test.
10.
The ohmmeter pointer should go to zero. If the
pointer stops between 2 and 3, that’s okay.
11.
After three minutes, remove one 2,000 ohm
resistor wire from the primary control. The
primary should lock out on safety within 25
seconds,
12.
After the primary locks out, the ohmmeter pointer
should move to near the 50 mark on the scale.
13.
Wait three minutes, then perform the following
steps in the right order:
a.
Remove the 2,000 ohm resistor from the
primary control.
b.
Remove the jumper wire from the primary
control thermostat terminals.
c.
Attach the cad cell wires to the primary
control.
d.
Attach the thermostat wires to the primary
control.
e.
Push the primary control reset button.
f.
Set the ohmmeter range to 100 MA when it
is not going to be used.
14.
Turn the heater thermostat all the way to the
right. The burner should start. Reset the
thermostat to the appropriate temperature.
5B. Control & Cad Cell
Trouble-Shooting Guide
Symptom
Possible Cause
Step 2.
Burner runs all the time
Defective primary
control
Step 8.
No combustion
No power to the
primary.
Limit switch turned
off.
Defective limit
switch.
Bad wire connection.
Bad burner motor.
No power from fuse
box.
Defective primary
Step 10.
Ohmmeter pointer above 2.
Partly plugged
nozzle.
Cad cell dirty.
Cad cell misaligned.
Defective cell.
Ohmmeter pointer below 3
Not enough
combustion air.
Cad cell sees too
much light.
Adjust alignment.
Step 11.
Primary won’t lock out
Defective primary
Step 12.
Ohmmeter pointer below 50
Stray light in burner
housing.
Defective cad cell.
Step 14.
Burner won’t start
Open circuit in
thermostat wiring.
Dirty thermostat
contacts.
Defective thermostat.
Step 14.
