Operating instructions

II. PRIME CONDENSATE TRAP WITH WATER
CAUTION: Condensate trap must be PRIMED or
proper draining may not occur. The condensate trap has 2
internal chambers which can ONLY be primed by pour-
ing water into the inducer drain side of condensate trap.
1. Remove upper inducer housing drain connection cap. (See
Fig. 42.)
2. Connect field-supplied 1/2-in. ID tube to upper inducer
housing drain connection.
3. Insert field-supplied funnel into tube.
4. Pour 1 quart of water into funnel/tube. Water should run
through inducer housing, overfill condensate trap, and flow
into open field drain. (See Fig. 43.)
5. Remove funnel and tube from inducer housing and replace
drain connection cap and clamp.
III. PURGE GAS LINES
If not previously done, purge lines after all connections have been
made and check for leaks.
WARNING: Never purge a gas line into a combustion
chamber. Never use matches, candles, flame, or other
sources of ignition for purpose of checking leakage. Use
a soap-and-water solution to check for leakage. Failure to
follow this warning could result in fire, explosion, per-
sonal injury, or death.
IV. ADJUSTMENTS
A. Set Gas Input Rate
Furnace gas input rate on rating plate is for installations at altitudes
up to 2000 ft. Furnace input rate must be within ±2 percent of input
on furnace rating plate.
1. Determine natural gas orifice size and manifold pressure for
correct input.
a. Obtain average yearly heat value (at installed altitude)
from local gas supplier.
b. Obtain average yearly specific gravity from local gas
supplier.
c. Verify furnace model. Table 7 can only be used for
model 340MAV furnaces.
d. Find installation altitude in Table 7.
NOTE: For Canada altitudes of 2000 to 4500 ft, use U.S.A.
altitudes of 2001 to 3000 ft in Table 7.
e. Find closest natural gas heat value and specific gravity in
Table 7.
f. Follow heat value and specific gravity lines to point of
intersection to find orifice size and manifold pressure
settings for proper operation.
Fig. 42—Inducer Housing Drain Tube
A94208
Fig. 43—Filling Condensate Trap
A94209
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