GC9C80 Installation Manual
15
2. Measure the static pressure of the supply duct. (Positive
Pressure)
3.
:
Both readings may be taken simultaneously and
read directly on the manometer if so desired. If an air
-
junction with the furnace, the readings must also include
these components, as shown in the following drawing.
4.
If the total external static pressure exceeds the maximum
listed on the furnace rating plate, check for closed dampers,
registers, undersized or poorly laid out duct work.
Digital
Manometer
-
not covered under the warranty.
installed in the central return register or a side panel external
or in the return air duct work.
One of the most common causes of a problem in a forced
cause premature heat exchanger failure.