Sears 9MPD, N9MP2, N9MP1 manual Checks and Adjustments, Main Burner Flame Check, Adjust Pilot Burner

Models: 9MPD N9MP1 N9MP2

1 62
Download 62 pages 59.01 Kb
Page 38
Image 38

Condensate Line Raised by Base

25-20-52

8. Checks and Adjustments

Startup

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

tion Manual' or to the "Operating Instructions Label' on the fur- nace.

CAUTION

If any sparks, odors or unusual noises occur, immediately

shut OFF power to furnace. Check for wiring errors or

obstruction to blower.

Gas Supply Pressure

Gas supply pressure should be within minimum and maximum values listed on rating plate. Pressures a re usually set by gas sup- pliers.

Manifold Gas Pressure Adjustment

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

FIRE OR EXPLOSION HAZARD

Failure to turn OFF gas at shut off before connecting

manometer can result in death, personal injury and/or

property damage.

Turn OFF gas at shut off before connecting manometer.

Pilot Burner

10-11-65

Main Burner Flame Check

Allow the furnace to run approximately 10 minutes then inspect the main burner and pilot flames. See Figure 42.

Check for the following (Figure 42):

Stable and blue flames. Dust may cause orange tips or wisps of yellow, but flames MUST NOT have solid, yel- low 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.

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, 0.3 (8mm) water column. For altitudes 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 41. To adjust, remove cap from pilot adjusting screw on gas valve. Turn

screw counterclockwise to increase or clockwise to decrease flame as re uired. Re lace adhJstin screw ca .

E_

Main Burner

10-10-78

Temperature Rise Check

The blower speed MUST be set to give the correct air temperature rise through the furnace as marked on the rating plate. Tempera- ture rise is the difference between supply and return air tempera- tures.

44001 111400

Page 38
Image 38
Sears 9MPD, N9MP2, N9MP1 manual Checks and Adjustments, Main Burner Flame Check, Adjust Pilot Burner, Temperature Rise Check