Checking Furnace Input - Napoleon 9700 SERIES Installation And Operating Instructions Manual

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ALL REGULATOR ADJUSTMENTS MUST BE DONE BY A TRAINED, QUALIFIED
TECHNICIAN. IMPROPER MODIFICATIONS OR ADJUSTMENTS CAN RESULT IN FIRE OR
EXPLOSION CAUSING PROPERTY DAMAGE, SEVERE PERSONAL INJURY OR LOSS OF
7. Remove the manometer hose from the outlet pressure tap boss, and tighten the outlet pressure tap screw
using the 3/32" Allen wrench. (Clockwise, 7 in-lb minimum).
8. Turn on the gas supply and electrical power to the furnace.
9. Turn on system power and energize valve.
10. Using a leak detection solution or soap suds, check for leaks at pressure boss screw. Bubbles forming
indicate a leak. SHUT OFF GAS AND FIX ALL LEAKS IMMEDIATELY!
In some circumstances, high inlet pressure can be remedied with the use of an in line appliance regulator. If
an in line appliance regulator is used, ensure that it has the capacity to adequately handle the gas volume
required by the furnace and any other appliances receiving gas from the header serving the furnace.

13.3 CHECKING FURNACE INPUT

The natural gas supply pressure should be a maximum of 7" w.c. and minimum of 5" w.c. The burner manifold
pressure is factory set to 3.5" w.c. High Fire, 1.4" w.c. Low Fire. The input rating of the furnace is based on
1000 Btu/ft.³ gas with a specifi c gravity of 0.6.
Since heating values for the gas vary geographically, the actual furnace input and output will vary accordingly.
For example, natural gas with a 900 Btu/ft.³ heating value will reduce the input to 90% of the rated input.
Natural gas with a 1100 Btu/ft.³ heating value will increase the input to approximately 110% of the rated input.
This is not usually a problem; however, adjustments to compensate for this can be made by minor adjustments
to the burner manifold pressure or by changing the burner orifi ce size. Contact the fuel supplier for specifi c
heating content values.
Any adjustments to the burner manifold pressure should be carried out with the use of a manometer or
calibrated Magnehelic® gauge. Do not adjust the gas valve pressure regulator more than ±0.3" w.c. Refer to
Figure 33.
Heating Value of Gas x 3600
Input =
Time in Sec. for 1 cu. ft.
where:
• input is expressed in Btu/hr
• heating value of the gas is expressed in Btu/ft
• and time is the number of seconds required for
the test dial to indicate 1 cubic foot.
If using a gas meter with SI (metric) units:
• 1 cubic foot = 0.0283 cubic meters
• 1 cubic meter = 35.315 cubic feet
• 0.01 cubic meter = 0.3531 cubic feet
• 0.5 cubic meter = 1.766 cubic feet
W415-1064 / 11.11.11
WARNING
!
LIFE.
IMPORTANT:
NEVER ADJUST THE INPUT OF
THE FURNACE TO EXCEED THE
INPUT SHOWN ON THE RATING
PLATE.
3
!
FIGURE 33 - MANOMETER MEASURING GAS
MANIFOLD PRESSURE