Sears 9MPD125L20B1 Furnace User Manual


 
Condensate Line Raised by Base
25-20-52
8. Checks and Adjustments
Adjust Pilot Burner
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.
2.
3.
Remove the burner compartment door.
With gas OFF, connect manometer to tapped opening on
gas valve. Use manometer with a 0 to 15" water column
range.
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.
The furnace has a pilot flame to light the main burner. The flame
3 1
should surround /8' to /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.
Proper Flame
Adjustment
Pilot Burner
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 ofyellow, 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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