York DL-06, Руководство по установке, Страница: 66 / 84

167791-BIM-B-0606
66 Unitary Products Group
POST START CHECK LIST
1. Verify proper system pressures for both circuits.
2. Measure the temperature drop across the evaporator coil.
START-UP (GAS HEAT)
PRE-START CHECK LIST
Complete the following checks before starting the unit.
1. Check the type of gas being supplied. Be sure that it is
the same as listed on the unit nameplate.
2. Make sure that the vent outlet and combustion air inlet
are free of any debris or obstruction.
OPERATING INSTRUCTIONS
LIGHTING THE MAIN BURNERS
1. Turn “OFF” electric power to unit.
2. Turn room thermostat to lowest setting.
3. Turn gas valve counter-clockwise to “ON” position (see
Figure 29).
4. Turn “ON” electric power to unit.
5. If thermostat set temperature is above room tempera-
ture, the main burners will ignite. If a second stage of
heat is called for, the main burners for second stage heat
will ignite for the second stage heat.
POST START CHECKLIST
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 sup-
ply piping.
2. Check for correct manifold gas pressures. (See ’CHECK-
ING GAS INPUT’.)
3. Check the supply gas pressure. It must be within the lim-
its shown on the rating nameplate. Supply pressure
should be checked with all gas appliances in the building
at full fire. At no time should the standby gas pressure
exceed 10.5 in. or the operating pressure drop below 4.5
in for natural gas units. If gas pressure is outside these
limits, contact the local gas utility or propane supplier for
corrective action.
SHUT DOWN
1. Set the thermostat to the lowest temperature setting.
2. Turn “OFF” all electric power to unit.
3. Open gas heat access panel.
4. Turn gas valve clockwise to “OFF” position (See Figure
29).
MANIFOLD GAS PRESSURE ADJUSTMENT
This gas furnace has two heat stages. Therefore, the gas
valve has two adjustment screws located under a plastic pro-
tective cover. The second stage (100% input) adjustment
screw is adjacent to the “HI” marking on the valve and the
first stage (60% input) adjustment screw is located adjacent
to the “LO” marking on the valve (See Figure 29).
Manifold pressure adjustment procedure.
Adjust second stage (100% input) pressure first, then adjust
first stage (60% input) pressure.
1. Turn off all power to the unit.
2. Using the outlet pressure port on the gas valve, connect
a manometer to monitor the manifold pressure.
3. Remove plastic cap covering HI and LO pressure adjust-
ment screws.
4. Turn on power to the unit.
5. Set thermostat to call for second stage heat and start fur-
nace.
6. If necessary, using a screwdriver, turn the second stage
adjustment screw (adjacent to the “HI” marking on the
valve) clockwise to increase manifold pressure or coun-
terclockwise to decrease manifold pressure.
Be sure
not to over-fire the unit on second stage .
7. After the high manifold pressure has been checked,
adjust the thermostat to call for first stage heat.
8. If necessary, using a screwdriver, turn the first stage
adjustment screw (adjacent to the “LO” marking on the
This furnace is equipped with an automatic re-ignition
system. DO NOT attempt to manually light the pilot.
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could
result in serious injury, death or property damage.
Never test for gas leaks with an open flame. use a
commercially available soap solution made specifi-
cally for the detection of leaks to check all connec-
tions. A fire or explosion may result causing property
damage, personal injury or loss of life.