Unit installation

035-14445-000 Rev. F (0404)
Unitary Products Group 3
6. Remove the screws holding the burner assembly to the
vestibule panel. It may be necessary to remove the roll-
out switch bracket(s) to gain access to one or more of
these screws.
7. Remove the burner assembly. It should be possible to
swing the burner assembly out of the way without dis-
connecting the remaining wires.
8. With the burner assembly out of the way, simply slide the
NOx screens out of the heat exchanger tubes and dis-
card the screens.
9. Replace all components in reverse order. Reconnect all
wiring.
TESTS AND ADJUSTMENTS
The following tests must be performed at the time of conver-
sion following completion of the installation.
1. Connect a manometer to the pressure tap on both the
inlet and outlet side of the gas valve. Connect a power
supply and a propane gas supply to the unit, if not
already connected.
2. Turn on the propane gas supply and bleed air from the
gas supply lines at a point as close to the inlet or the gas
valve as is practical.
3. Turn the gas valve control switch to the ON position.
4. Make sure unit electrical disconnect switch is in the OFF
position.
5. Set the room thermostat to call for heat.
6. Turn unit electrical disconnect switch to ON. The com-
bustion blower should start and the hot surface igniter
should start glowing.
7. After air has been purged from the gas supply line, igni-
tion should occur. Shortly after ignition, the manifold and
gas inlet pressures can be checked on the manometers.
Main burner ignition may be delayed on the first ignition
cycle due to air in the gas manifold.
8. Adjust manifold pressure to 10.0" W.C. This setting will
result in a propane gas input which is the same as the
natural gas input found on the unit rating plate. (supply
gas must be supplied to the unit at a pressure of 11-13.9"
W.C.). Verify that the supply gas pressure is within the
range specified above. If required, adjust the incoming
regulator spring so that the pressure falls within the
range.
9. Observe several ignition cycles. All main burners must
ignite without delayed ignition or burning at the orifices. If
delayed ignition is observed, verify that the igniter is
properly mounted (not loose or crooked on bracket, and
that bracket screws are not loose).
10. If burning at the orifices, excessive yellow tipping, or
excessive noise is observed during any phase of main
burner operation, verify unit operation.
11. With the main burners ignited, check for gas leaks, espe-
cially in the following locations: gas valve inlet and outlet
connections, manifold union in the burner compartment,
and main burner orifices where they thread into the man-
ifold. Repair any leaks found and recheck.
12. During Unit Operation, the main burner appearance and
igniter location should be as shown below:
13. With the main burners off, disconnect the manometers
and replace the plugs. Check for gas leakage at the
plugs.
14. Replace all access panels.
Make sure both gas and power supplies are shut off
before proceeding
On 90+ AFUE models, refer to unit installation
instructions for proper procedure for connecting
manometer to furnace.
On 90+ AFUE furnaces, the gas valve regulator cap
must be in place to determine final gas pressure set-
ting.
FIGURE 1 - Gas Valve
Do not use an open flame
FIGURE 2 - Proper Burner Flame Appearance
OFF
ON
OUTLET
PRESSURE
PORT
OUTLET
MAIN
REGULATOR
ADJUSTMENT
ON/OFF
SWITCH
INLET
PRESSURE
PORT
WRENCH
BOSS
INLET
BLUE CONE PORTION OF
FLAME SHOULD ENTER
HEAT EXCHANGER TUBE