507867-02
Page 47 of 54
Issue 2128
speed to maintain the temperature rise within the range
shown on the unit nameplate. See Table 15 for allowable
heating speeds. 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.
Blower Control
The blower ON time of 30 seconds is not adjustable. The
blower OFF delay (amount of time that the blower operates
after the heat demand has been satisfied) may be adjusted
by changing the jumper position across the five pins on
the integrated control. The unit is shipped with a factory
heat blower OFF setting of 120 seconds. The blower
OFF delay affects comfort and is adjustable to satisfy
individual applications. Adjust the blower OFF delay to
achieve a supply air temperature between 90° and 110°F
at the moment that the blower is de-energized. Longer
OFF delay settings provide lower return air temperatures;
shorter settings provide higher return air temperatures.
Figure 70.
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
access panel in place.
Motor Nameplate__________Actual__________
Blower Speeds
Follow the steps below to change the blower speeds.
1. Turn off electrical power to furnace.
2. Remove blower access panel.
3. Disconnect existing speed tap at control board speed
terminal.
NOTE:
Termination of any unused motor leads must
be insulated.
4. Place unused blower speed tap on integrated control
“PARK” terminal or insulate.
5. Refer to blower speed selection chart on unit wiring
diagram for desired heating or cooling speed. See
Blower performance data beginning on the next page.
See Table 15 for allowable heating speeds.
6. Connect selected speed tap at control board speed
terminal.
7. Re-secure blower access panel.
8. Turn on electrical power to furnace.
9. Recheck temperature rise.
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 flame rollout switches
on burner box assembly if necessary.
