York GF9S*DH UIM-B-0607, Adjustment Of Temperature Rise, Adjustment Of Fan Control Settings

WITH BURNER BOX COVER IN PLACE

268890-UIM-B-0607

WITH BURNER BOX COVER REMOVED

TEEGAS

FITTING VALVE

BURNER BOX

PRESSURE

REFERENCE

HOSE

	6
	5
	4
	3
U-TUBE	2
	1
MANOMETER	0
	1
	2
	3
	4
	5
	6

3.5 IN

WATER COLUMN GAS PRESSURE SHOWN

GAS VALVE

BURNER BOX

PRESSURE

REFERENCE

HOSE

	6
	5
	4	3.5 IN
U-TUBE	3
	2	WATER COLUMN
MANOMETER	1
	0	GAS PRESSURE
	1
	2	SHOWN
	3
	4
	5
	6

FIGURE 39: Reading Gas Pressure

ADJUSTMENT OF TEMPERATURE RISE

The temperature rise, or temperature difference between the return air and the supply (heated) air from the furnace, must be within the range shown on the furnace rating plate and within the application limitations shown in Table 7 “ELECTRICAL AND PERFORMANCE DATA”.

The supply air temperature cannot exceed the “Maximum Supply Air Temperature” specified in these instructions and on the fur- nace rating plate. Under NO circumstances can the furnace be allowed to operate above the Maximum Supply Air Temperature. Operating the furnace above the Maximum Supply Air Temperature will cause premature heat exchanger failure, high levels of Carbon Monoxide, a fire hazard, personal injury, property damage, and/or death.

The temperature rise, or temperature difference between the return air and the heated supply air from the furnace, must be within the range shown on the furnace rating plate and within the application limitations as shown in Table 7.

After about 20 minutes of operation, determine the furnace temperature rise. Take readings of both the return air and the heated air in the ducts, about six feet (1.83 m) from the furnace where they will not be affected by radiant heat. Increase the blower speed to decrease the temperature rise; decrease the blower speed to increase the rise.

TWIN

FAN OFF
ADJUSTMENT	Y/Y2	180	120	60 90
JUMPER			DELAY	BLOWER OFF
	W
	R
	G
	C

FIGURE 40: Furnace Control Board

All direct-drive blowers have multi-speed motors. The blower motor speed taps are located in the control box in the blower compartment. Refer to Figure 40, and the unit-wiring label to change the blower speed. To use the same speed tap for heating and cooling, the heat ter- minal and cool terminal must be connected using a jumper wire and connected to the desired motor lead. Place all unused motor leads on Park terminals. Two are provided.

Do not energize more than one motor speed at a time or damage to the motor will result.

ADJUSTMENT OF FAN CONTROL SETTINGS

This furnace is equipped with a time-on/time-off heating fan control. The fan on delay is fixed at 30 seconds. The fan off delay has 4 settings (60, 90, 120 and 180 seconds). The fan off delay is factory set to 120 sec- onds. The fan-off setting must be long enough to adequately cool the furnace, but not so long that cold air is blown into the heated space. The fan-off timing may be adjusted by positioning the jumper on two of the four pins as shown in Figure 40.

The blower speed connections shown in Figure 40 are typical. How- ever, these connections may vary from model to model and may be changed as needed to give proper heating and cooling airflow.

PARK PARK		YELLOW-MED. LOW
		RED-LOW
	HI COOL	BLACK-HI
	HEAT	BLUE-MED. HI
	EAC-H
	L1
	XFMR
NEUTRALS

HUM

Unitary Products Group 35