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2. Fuel pump not operating, coupler loose, bypass in pump stuck open.
3. Water, paint, or antifreeze in oil.
4. Failure of pre heater(s) in slide gun assembly. Slide gun underside should feel warm.
5. Electrodes improperly adjusted, broken, shorting, or ash covered.
6. Centrifugal switch in model 500 burner motor failing (green light flickers or never on).
Primary Control Locks Out On Safety
1. The cad cell (electronic eye) detects a reduced, dirty or no flame for over 30 seconds. A
signal measured in ohms is communicated between the cad cell and the primary control
“F – F” connections. A poor or absent flame produces a high ohm reading. When this
signal is > 1500 ohms the control goes into reset. A signal indicating a very good flame is
< 500 ohms. A moderate flame would be 500 to 1000 ohms. Contact your dealer for
details on reading ohms at the safety control.
2. The cad cell has failed, lens is dirty, or retention head is dirty.
3. The retention head fins are not allowing light to pass to the cad cell.
4. The cad cell receptacle is not making good contact with the cell.
5. The primary control is defective allowing the reset button to pop too easily.
6. Exhaust fan in building reverses draft in chimney, or cold building at night creates down
draft. The flame smokes on startup due to lack of proper draft and trips reset.
Smoke On Ignition
1. Oil flow too great--adjust flow downward.
2. Air pressure too low (set approximately 13 psi and adjust as needed).
3. Down draft, or improper draft adjustments, check barometric damper regulator. Install a
draft inducer if reverse draft is present due to cold building or exhaust fans.
Heater Cycles On and Off Due to High Limit on Fan Switch
1. Indicator is the amber light cycles on & off. Causes may be: oil pressure is set too high
and burner over fires, blower is restricted, or louvers are restrictive, or fan switch is failing.
Check for air flow restrictions and set flame to proper size. Correct before damage is done
to exchanger or chimney.
Poor Draft
1. Confirm there is -.04 to -.06 inches water column at breech of exchanger.
2. Firebox, flue outlet, or stack is plugged with ash.
3. Exhaust fan in building reverses draft in chimney.
4. Cold building at night creates down draft in chimney.
5. Height of chimney insufficient or pipe cap plugged or blown off.
6. Lack of make up air for combustion.
7. Install a draft inducer if reverse draft is present due to cold building or exhaust fans.
Summary of Contents for 155
Page 21: ...Page 21 of 21 APPLIES TO ALL HEATER MODELS EXCEPT MODEL 500 ...
Page 23: ...Page 23 of 23 MODEL 500 HEATER ONLY 220 VAC FEED ...
Page 27: ...Page 27 of 27 K5 Burner w Air Pump 1 of 2 Burner Drawing ...
Page 28: ...Page 28 of 28 K5 Burner w Air Pump 2 of 2 Burner Drawing ...
Page 29: ...Page 29 of 29 B5 Burner Drawing ...
Page 30: ...Page 30 of 30 B5 Burner Drawing ...
Page 33: ...Page 33 of 33 120 VOLT MODEL B5 TWO STAGE w AIR DELAY BURNER WIRING ...
Page 55: ...Page 55 of 55 BLUE CABINET MODEL 235 ...
Page 63: ...Page 63 of 63 BURNERS ...
Page 65: ...Page 65 of 65 BURNERS CONTINUED ...