Temperature Rise

Temperature Rise

Check the temperature rise and, if necessary, adjust the blower speed to maintain the temperature rise within the range shown on the unit rating plate.

Electro-mechanical Thermostat Heat Anticipation

In single-stage heat applications, set the heat anticipation to 0.2 amps.

In two-stage heat applications, set the heat anticipation to

0.26amps and install a field-provided resistor (150 ohm, 10 watt rating −Lennox part number P−8−6256) in parallel with K13 relay coil.

Electrical

1 − Check all wiring for loose connections.

2 − Check for the correct voltage at the furnace (furnace operating).

3 − Check amp-draw on blower motor. Motor service factor amps

Nameplate __________Actual__________

Flue And Chimney

1 − Check flue pipe, chimney and all connections for tight- ness and to make sure there is no blockage.

2 − Check unit for proper draft.

3 − Are pressure switches closed? Obstructed flue will open pressure switches and cause unit to shut down. Check flue and outlet for blockages.

4 − Reset manual flame rollout switches on burner box covers.

Burner Flame Adjustment

The G24−200 burner flame is not adjustable; however, the flame should be inspected at the beginning of each heating season. If necessary, clean the burners. Burner flame should be blue when burning natural gas. See figure 21.

BURNER FLAME

FLAME

FLAME APPEARS

 

BLUE IF BURNING

 

NAT. GAS.

HEAT

 

 

EXCHANGER

BURNER

TUBE

 

VEST

PANEL

FIGURE 21

Failure To Operate

If unit fails to operate check the following: 1 − Is the thermostat calling for heat?

2 − Are access panels securely in place?

3 − Is the main disconnect switch closed?

4 − Is there a blown fuse or tripped circuit breaker?

5 − Are the filters dirty or plugged? Dirty or plugged filters will cause the limit controls to shut the unit off.

6 − Is gas turned on at the meter?

7 − Is the manual main shut-off valve open?

8 − Are the internal manual shut-off valves open?

9 − Are the unit ignition systems in lock out mode? If unit locks out again, call serviceman to inspect unit for block- ages.

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Lennox International Inc G24-200 installation instructions Temperature Rise