55
Marvair GAA A/C w/Gas Heat I&O Manual
06/2023 Rev.5
11. After reassembly, turn on the gas and check for leaks using a soapy solution. Correct all leaks
immediately.
12. Turn power back on to the unit.
13. Turn gas ON at the shut off valve.
5.8 Main Burner Flame Check
Allow the furnace to run for at least 10 minutes. Then inspect the main burner flame.
Look at the flames on the burners. They should be predominately blue in color and robust in appearance.
The flame should be in the middle of the heat exchanger tubes. Check to see that all the burners are lit
and that the flame does not impinge on the sides of the heat exchanger. Observe the flame. There should
be little or no change to the shape or size of the flame. Changes in the shape and size of the flame may
indicate a leak in the heat exchanger. See Figure 10.
Figure 11. Burner Flame
Distorted flame or yellow tips of the natural gas flame or long yellow tips on LP gas flames may be caused
by one or more of the following:
1. Lint or dirt inside the burner or burner ports,
2. Lint or dirt at the air inlet between the burner and the manifold pipe, or
3. An obstruction over the burner plate.
If any of these are visible, turn the unit off and use a vacuum or a soft brush to clean the affected areas.
5.9 Temperature Rise Range
When the unit is in the heating mode, the inlet air and outlet air temperatures should be measured to ensure
that the temperature rise ( the difference between the outlet air temperature and the inlet air temperature ) is
within an acceptable range as shown below. The temperatures must be measured at the discharge of the
supply and the intake of the return air with no more than a .35 IWG static pressure.
Heating Input
( Btu / Hr )
Temperature Rise at 0.35” H2O External Static Pressure ( °F )
Gas / Electric Model Number
GAA1024A
GAA1030A
GAA1036A
GAA1042A
GAA1048A
GAA1060A
45,000
25 to 55
25 to 55
25 to 55
67,500
40 to 70
40 to 70
40 to 70
90,000
50 to 80
50 to 80
50 to 80
75,000
25 to 55
25 to 55
25 to 55
100,000
40 to 70
40 to 70
40 to 70
125,000
50 to 80
50 to 80
50 to 80
Table 8. Temperature Rise Range
