Sterling QVEF - Manual (Page 14)

14
OPERATION
POWER VENTED PROPELLER UNITS
INTERMITTENT (SPARK) PILOT IGNITION
START-UP (Also refer to lighting instruction plate
equipped on the unit)
1. Open the manual valve supplying gas to the unit
heater, and with the union connection loose, purge
air from the gas line. Tighten the union and check for
gas leaks using a soapy water solution only.
Never use an open fl ame to detect
gas leaks. Explosive conditions may exist which
could result in personal injury or death.
Before attempting to light or
relight pilot, wait 5 minutes to allow gas which
may have accumulated in the burner compart-
ment to escape. Failure to do so could cause
the accumulated gas to ignite rapidly, leading to
personal injury or death.
2. Open the manual valve on the unit heater.
3. Turn ON electrical power.
4. The unit should be under the control of the
thermostat. Turn the thermostat to the highest point
and determine that the power venter motor starts,
and the pilot and main burners ignite. Turn the
thermostat to the lowest point and determine that
the power venter motor shuts off and the pilot and
main burners are extinguished.
5. If pilot adjustment is required, remove the pilot
adjustment seal cap and adjust the pilot screw to
obtain proper fl ame. Clockwise rotation decreases
pilot fl ame size. Replace the cap.
6. Turn the thermostat to the desired position.
7. See Gas Input Rate and Adjustments sections.
SHUT DOWN
1. Turn the valve selector knob to the “OFF” position.
2. Turn off the electricity.
3. To relight, follow the “start-up” instructions.
See Figure 11 for parts/identifi cation.
EXPLANATION OF CONTROLS (See Figure 11):
1. The unit heater is equipped with a power venter
system consisting of a power venter motor and
blower, pressure switch, and sealed fl ue collector in
place of the conventional draft diverter.
The addition of external draft
hoods or power ventors is not permitted.
Addition of such devices may cause severe
unit malfunction or failure!
2. The power venter motor is energized
by the room thermostat on a call for heat. The
pressure switch measures the fl ow through the vent
system and energizes the indirect spark ignition
system when the fl ow is correct.
T h e p r e s s u r e s w i t c h M U S T
NOT be bypassed. The unit MUST NOT be fi red
unless the power ventor is operating. An unsafe
condition could result.
3. The indirect spark ignition system consists of
an ignition control module, a dual combination
valve, and a spark-ignited pilot burner. When the
pressure switch closes, the pilot valves opens and
a spark is generated to light the pilot burner. When
fl ame sensing circuit senses that the pilot fl ame is
established, the main gas valve is opened to supply
gas to the main burners. When the thermostat is
satisfi ed, the vent system is deenergized and both
valves are closed to stop all fl ow of gas to the unit.
4. The limit switch interrupts the fl ow of electric current
to the main gas valve in case the heater becomes
overheated.
5. The fan switch delays the operation of the fan until
the heater is warmed, then keeps the fan running
after the gas has been turned off until the useful heat
has been removed. The startup fan delay must not
exceed 90 seconds from a cold start.
6. The wall ther mostat (supplied optionally) is a
temperature sensitive switch which operates the
vent system and the ignition system to control the
temperature of the space being heated. It must be
mounted on a vibration free, vertical surface away
from air currents, in accordance with the instructions
furnished with the thermostat (also refer to Electrical
Section).