Frymaster BIH52 - Manual (Page 41)

3-24
Check for proper operation by disconnecting the wire from the ignitor (spark plug), inserting the tip
of a screw driver into the terminal, and holding it near the frame of the fryer as the power switch is
placed in the ON position. A strong, blue spark should be generated for at least 4 seconds.
DANGER
MAKE SURE YOU ARE HOLDING THE INSULATED HANDLE OF THE SCREWDRIVER
AND NOT THE BLADE. THE SPARKING CHARGE IS APPROXIMATELY 25,000
VOLTS.
Examine the ignitor (spark plug) for any signs of cracking. A cracked ignitor must be replaced.
If all other causes have been ruled out, examine the burner tiles for any signs of cracking. If found,
the burner must be replaced.
Fluctuating flame intensity is normally caused by either improper or fluctuating incoming gas pres-
sure, but may also be the result of variations in the kitchen atmosphere. Verify incoming gas pres-
sure in the same way as for “popping,” discussed in the preceding paragraphs. Variations in the
kitchen atmosphere are usually caused by air conditioning and/or ventilation units starting and stop-
ping during the day. As they start and stop, the pressure in the kitchen may change from positive or
neutral to negative, or vice versa. They may also cause changes in airflow patterns that may affect
flame intensity.
Dark spots on the burner tiles are the result of an improper air/gas mixture. Adjust the combustion
air blower to reduce the amount of air in the mixture to correct this problem.
Flames shooting out of the flue are usually an indication of negative pressure in the kitchen. Air is
being sucked out of the burner enclosure and the flames are literally following the air. If negative
pressure is not the cause, check for high burner manifold gas pressure in accordance with the proce-
dures on page 2-6.
An excessively noisy burner, especially with flames visible above the flue opening, may indicate
that the gas pressure is too high, or it may be that, on non-CE units, the gas valve vent tube is
blocked. If the incoming gas pressure is correct and the vent tube on non-CE units is unobstructed,
the gas valve regulator is probably defective.
Occasionally a burner may apparently be operating correctly, but nevertheless the fryer has a slow
recovery rate (the length of time required for the fryer to increase the oil temperature from 270ºF to
320ºF (133ºC to 160ºC)). The primary causes of this are an over-filled vat, a dirty or out-of-
adjustment combustion air blower, low burner manifold pressure, and/or damaged burner tiles.
Adding oil to the frypot during the recovery process will also cause a slow recovery rate. If these
causes are ruled out, the probable cause is a misadjusted gas valve regulator. Refer to page 2-6 for
the procedure for checking the pressure of gas supplied to the burner.
3.7.3 Improper Temperature Control
Temperature control, including the melt cycle, is a function of several interrelated components, each
of which must operate correctly. The principle component is the temperature probe. Other compo-
nents include the interface board, the controller itself, and the ignition module.