284809-YIM-B-0707
54
Unitary Products Group
TO SHUT DOWN:
1. Turn “off” electric power to unit.
2. Depress knob of gas valve while turning to “off”
position, or turn gas valve switch to “off” position.
POST-START CHECK LIST (GAS)
After the entire control circuit has been energized and
the heating section is operating, make the following
checks:
1. Check for gas leaks in the unit piping as well as the
supply piping.
2. Check for correct manifold gas pressures. See
“Checking Gas Input” page 55.
3. Check the supply gas pressure. It must be within
the limits shown on rating nameplate. Supply pres-
sure should be checked with all gas appliances in
the building at full fire. At no time should the
standby gas line pressure exceed 13", nor the
operating pressure drop below 5.0" for natural gas
units. If gas pressure is outside these limits, con-
tact the local gas utility for corrective action.
MANIFOLD GAS PRESSURE ADJUSTMENT
Small adjustments to the high-fire gas flow may be
made by turning the pressure regulator adjusting screw
on the automatic gas valve.
Adjust as follows:
1. Remove the cap on the regulator. It's located next
to the push-on electrical terminals.
2. To decrease the gas pressure, turn the adjusting
screw counterclockwise.
3. To increase the gas pressure, turn the adjusting
screw clockwise.
NOTE:
The correct manifold pressure for these fur-
naces is 3.65 IWG ±0.3.
FIRE OR EXPLOSION HAZARD
FAILURE TO FOLLOW THE SAFETY WARN-
ING EXACTLY COULD RESULT IN SERIOUS
INJURY, DEATH OR PROPERTY DAMAGE.
NEVER TEST FOR GAS LEAKS WITH AN
OPEN FLAME. USE A COMMERICALLY
AVAILABLE SOAP SOLUTION MADE SPE-
CIFICALLY FOR THE DETECTION OF
LEAKS TO CHECK ALL CONNECTIONS. A
FIRE OR EXPLOSION MAY RESULT CAUS-
ING PROPERTY DAMAGE, PERSONAL
INJURY OR LOSS OF LIFE.
FIGURE 25 - TYPICAL GAS VALVES
FIGURE 26 - PROPER FLAME ADJUSTMENT
1 / 8 " G A P B E T W E E N C A R R Y - O V E R
T U B E A N D F L A M E S E N S O R B U L B
C A R R Y - O V E R T U B E
F L A M E S E N S O R B U L B
B U R N E R A S S E M B L Y B R A C K E T
