Specifications

440 01 1024 04
Specifications are subject to change without notice
43
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in
personal injury, death and/or property damage.
If any sparks, odors or unusual noises occur,
immediately shut OFF power to furnace. Check for
wiring errors or obstruction to blower.
WARNING
Manifold Gas Pressure Adjustment
NOTE: Make adjustment to manifold pressure with burners
operating.
1. Remove the burner compartment door.
2. Remove the blower compartment door. Place a jumper
across furnace controls R to W. Replace blower
compartment door.
3. With gas OFF, connect manometer to tapped opening on
gas valve. Use manometer with a 0 to 15 inch water column
range.
4. Turn gas ON and remove adjustment screw cover on gas
valve. Turn adjusting screw counterclockwise to decrease
manifold pressure and clockwise to increase pressure.
Figure 45 Typical Gas Control Valve
Regulator Adjustment
Under Cap
Inlet
Pressure
Tap
1
/
8
NPT
INLET
OUTLET
Outlet
Pressure
Tap
1
/
8
NPT
IN
OFF
ON
HONEYWELL
NOTE: Adjustment screw cover MUST be replaced on gas control
valve before reading manifold pressure and operating furnace.
5. Set manifold pressure to value as shown in Table 9,
Table 10, Table 11 or Table 12 under GAS SUPPLY AND
PIPING section in this manual.
6. When the manifold pressure is properly set, replace the
adjustment screw cover on the gas control valve.
7. Remove blower compartment door. Remove jumper wire
from thermostat connection on furnace control board.
Remove manometer connection from manifold pressure
tap, and replace plug in manifold.
8. Check for leaks at plug.
9. Replace the burner and blower compartment doors.
Natural Gas Input Rating Check
NOTE: The gas meter can be used to measure input to furnace.
Rating is based on a natural gas BTU content of 1,000 BTU’s per
cubic foot. Check with gas supplier for actual BTU content.
1. Turn OFF gas supply to all appliances and start furnace.
Use jumper wire on R to W for Heat.
2. Time how many seconds it takes the smallest dial on the gas
meter to make one complete revolution. Refer to Example.
NOTE: If meter uses a 2 cubic foot dial, divide results
(seconds) by two.
Example (BTUH)
Natural Gas
BTU Content
No. of
Seconds
Per Hour
Time Per
Cubic Foot in
Seconds
BTU Per
Hour
1,000 3,600 48 75,000
1,000 x 3,600 ÷ 48 = 75,000 BTUH
To Determine the appliance kW input rate from a .05m
3
test dial
that has been clocked at 80 seconds for one complete revolution.
Example (kW)
Number of
seconds per
hour
Number of
seconds per
complete
rotation
Size of test dial
(.05m
3
)
kW m
3
/h
3,600 80 .05 2.25
3,600 ÷ 80 x .05 = 7.2 m
3
/h
2.25m
3
/h x 10.35 kWh/m
3
= 23.28 kW
23.28 x 3.412 = 79,431 BTU
3. Remove jumper wire from R to W.
4. Relight all appliances and ensure all pilots are operating.
Main Burner Flame Check
Allow the furnace to run approximately 10 minutes then inspect the
main burner. See Figure 46.
Check for the following (Figure 46):
• Stable and blue flames. Dust may cause orange tips or
wisps of yellow, but flames MUST NOT have solid, yellow
tips.
• Flames extending directly from burner into heat
exchanger.
• Flames do NOT touch sides of heat exchanger
.
If any problems with main burner flames are noted, it may be
necessary to adjust gas pressures, or check for drafts.
Main Burner
Burner Face
10−10−78
Figure 46
NOTE: For Ignitor location see Figure 47.
Ignitor Location in(mm)
Figure 47
NOTE: Flame sensor has a different orientation in all 050 models.
5
/
16
(8)
1
/
4
(6.4)
2
1/
16
(52.4)