Installation Guide
507052-04 Page 47 of 53Issue 1727
Capacity
Natural to LP/
Propane
High Altitude Natural
Burner Orice Kit
High Altitude LP/
Propane Burner
Orice Kit
High Altitude Pressure Switch
0 - 7500 ft
(0 - 2286m)
7501 - 10000 ft
(2286 - 3048m)
7501 - 10000 ft
(2286 - 3048m)
4501 - 7500 ft
(1371 - 2286m)
7501 - 10000 ft
(2286 - 3048m)
045
11K48 *51W01 11K47
14A47 14A50
070 14A55 14A56
090 14A54 14A53
110 14A46 14A51
*Conversion requires installation of a gas valve manifold spring which is provided with the gas conversion kit.
Pressure switch is factory set. No adjustment necessary. All models use the factory-installed pressure switch from 0-4500 feet (0-1371 m).
Table 17. Conversion Kit Fan Pressure Switch Requirements at Varying Altitudes
High Altitude Information
NOTE: In Canada, certication for installations at
elevations over 4500 feet (1371 m) is the jurisdiction of
local authorities.
Units may be installed at altitudes up to 10,000 ft. above
sea level without manifold adjustment. Units installed
at altitude of 4501 - 10,000 feet (1371 to 3048 m) may
require a pressure switch change which can be ordered
separately. Table 17 lists conversion kit and pressure
switch requirements at varying altitudes.
The combustion air pressure switch is factory-set and
requires no adjustment.
NOTE: A natural to LP/propane gas changeover kit is
necessary to convert this unit. Refer to the changeover kit
installation instruction for the conversion procedure.
Other Unit Adjustments
Primary Limit
The primary limit is located on the heating compartment
vestibule panel. This limit is factory set and requires no
adjustment.
Flame Rollout Switches (Two)
These manually reset switches are located on the front of
the burner box. These limits are factory set and require no
adjustment.
Pressure Switch
The pressure switch is located in the heating compartment
on the cold end header box. This switch checks for proper
combustion air inducer operation before allowing ignition
trial. The switch is factory set and must not be adjusted.
Temperature Rise
After the furnace has been started and supply and return
air temperatures have been allowed to stabilize, check the
temperature rise. If necessary, adjust the blower speed to
maintain the temperature rise within the range shown on
the unit nameplate. Increase the blower speed to decrease
the temperature. Decrease the blower speed to increase
the temperature rise. Failure to adjust the temperature rise
may cause erratic limit operation.
Fan Control
The fan ON time of 30 seconds is not adjustable. The fan
OFF delay (amount of time that the blower operates after
the heat demand has been satised) is 120 seconds and
is not adjustable.
Thermostat Heat Anticipation
Set the heat anticipator setting (if adjustable) according to
the amp draw listed on the wiring diagram that is attached
to the unit.
Electrical
1. Check all wiring for loose connections.
2. Check for the correct voltage at the furnace (with
furnace operating). Correct voltage is 120 VAC ± 10%.
3. Check amp–draw on the blower motor with the blower
compartment access panel in place.
Motor Nameplate__________Actual__________
Electronic Ignition
The integrated control has an added feature of an internal
Watchguard control. The feature serves as an automatic
reset device for integrated control lockout caused by
ignition failure. This type of lockout is usually due to low
gas line pressure. After one hour of continuous thermostat
demand for heat, the Watchguard will break and remake
thermostat demand to the furnace and automatically reset
the integrated control to begin the ignition sequence.
Exhaust and Air Intake Pipe
1. Check exhaust and air intake connections for tightness
and to make sure there is no blockage.
2. Is pressure switch closed? Obstructed exhaust pipe
will cause unit to shut off at pressure switch. Check
termination for blockages.
3. Obstructed pipe or termination may cause rollout
switches to open. Reset manual ame rollout switches
on burner box assembly if necessary.