Sears N9MP2075B12B1 Checks and Adjustments, Gas SupplyPressure, Startup, Adjust Pilot Burner

Condensate Line Raised by Base

25-20-52

8. Checks and Adjustments

FIRE OR EXPLOSION HAZARD.

Failure to turn OFF gas at shut off before

connecting manometer could result in death, personal injury and/or property damage.

Turn OFF gas at shut off before connecting manometer.

Startup

NOTE: Refer to the start-up procedures in the "User's Information

Manual' or to the "Operating Instructions Label' on the furnace.

FIRE OR EXPLOSION HAZARD.

Failure to correct hazard could result in death, personal injury, 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.

Gas SupplyPressure

Gas supply pressure should be within minimum and maximum val- ues listed on rating plate. Pressures are usually set by gas suppli- ers.

Manifold Gas Pressure Adjustment

NOTE: Make adjustment to manifold pressure with burners oper- ating.

1.Remove the burner compartment door.

2.With gas OFF, connect manometer to tapped opening on gas valve. Use manometer with a 0 to 15" water column range.

3.Turn gas ON and remove adjustment screw cover on gas

valve. Turn counterclockwise to decrease pressure and clockwise to increase.

4.For altitudes up to 2000', set pressure to value shown in Table 6 or Table 8, _+0.3" (8ram) water column. For alti-

tudes of 2000' to 8000', see Section 5 for correct pressure setting.

Adjust Pilot Burner

The furnace has a pilot flame to light the main burner. The flame should surround 3/8' to 1/2' of the flame sensor. See Figure 42. To

adjust, remove cap from pilot adjusting screw on gas valve. Turn

screw counterclockwise to increase or clockwise to decrease

flame as required. Replace adjusting screw cap.

Pilot Burner

Proper Flame

Adjustment

3/8" to 1/2"

Hot Surface

Igniter

10-11-65

Main Burner Flame Check

Allow the furnaceto run approximately 10 minutes then inspect the main burner and pilot flames. See Figure 43.

Check for the following (Figure 43):

•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 ex- changer.

•Flames do NOT touch sides of heat exchanger.

If any problems with main burner flames are noted, it may be nec- essary to adjust gas pressures, or check for drafts.

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