CHECKING THE INPUT
For appliance installation locations with elevations above 2000 feet, refer to HIGH ALTITUDE INSTALLATIONS section of this manual for input reduction procedure.
1.Attach a pressure gauge or a manometer to the manifold pressure tap on the gas valve and refer to Table 10, for correct manifold pressure.
2.Use this formula to “clock” the meter. Be sure that other gas consuming appliances are not operating during this interval.
(3600/T) x H = Btuh
T = Time in seconds to burn one cubic foot of gas. H = Btu’s per cubic foot of gas.
Btuh = Actual heater input.
Example: (Using N100 250NE heater) T = 15.1 seconds
H = 1050 Btu Btuh = ?
(3600/15.1) x 1050 = 250,000 (Compare with N100 250NE model and rating.)
Should it be necessary to adjust the gas pressure to the burners to obtain the full input rate, the steps below should be followed:
3.Remove the regulator adjustment sealing cap and adjust the pressure by turning the adjusting screw with a screwdriver. See Figure 25.
Clockwise to increase gas pressure and input rate.
Counterclockwise to decrease gas pressure and input rate.
4.“Clock” the meter as in step 2 above.
5.Repeat steps 3 and 4 until the specified input rate is achieved.
6.Turn the gas control knob to PILOT. Remove the pressure gauge and replace the sealing cap and the Allen wrench set screw in the pressure tap opening.
UNDER NO CIRCUMSTANCES SHOULD THE GAS INPUT EXCEED THE INPUT SHOWN ON THE HEATER MODEL AND RATING PLATE. OVERFIRING COULD RESULT IN DAMAGE OR SOOTING OF THE HEATER.
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