YFG255 SERIES GAS RETHERMALIZERS
CHAPTER 1: SERVICE PROCEDURES
1-16
Fluctuating flame intensity
is normally caused by either improper or fluctuating incoming gas
pressure, but may also be the result of variations in the kitchen atmosphere. Verify incoming gas
pressure 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 systems starting and
stopping during the day. As air conditioning/ventilation systems start and stop, the pressure in the
kitchen may change from positive or neutral to negative, or vice versa. Changes in airflow patterns
may affect flame intensity.
Flames
"
rolling
"
out of the rethermalizer
are usually an indication of negative pressure in the
kitchen. Air is being sucked out of the rethermalizer 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 procedures in Section 1.4. An obstructed flue, which prevents the rethermalizer
from properly exhausting, may also be the cause.
Excessively noisy burners
, especially with
flames visible above the flue opening
, may indicate that
the burner gas pressure is too high, the tube diffusers are defective or burned out, or it may simply be
that the gas valve vent-tube is blocked (if applicable). If the gas pressure is correct, the tube
diffusers are intact and in good condition, and the vent-tube is unobstructed (if applicable), the gas
valve regulator is probably defective.
1.6.3 Improper Temperature Control
Temperature control is a function of several interrelated components, each of which must operate
correctly. The principal component is the temperature probe. Depending upon the specific
configuration of the rethermalizer, other components may include the controller itself, the
temperature probe, and the ignition module.
Improper temperature control problems can be failure to control at setpoint.
Failure to Control at Setpoint
The problem may be with the temperature probe or the controller. Refer to the troubleshooting
guides in this chapter.