Rheem GF901U Series Installation Instructions Manual page 38

Remove the plug from the 2" alternate
drain hole (see Figure 34) and
replace it with the 2" rubber grommet
supplied in the RXGY- H01 downflow
alternate drain kit. Also, remove the
1-5/8" grommet supplied in the
primary drain hole and replace it with
the 1-5/8" diameter plug that is also
supplied in the RXGY-H01 downflow
alternate drain kit. Both the hole-plug
and grommet must be in place to
insure a good seal in the burner
compartment.
1
A length of / " black PVC pipe is also
2
provided in the RXGY-H01 downflow
alternate drain kit. Glue one end of
the pipe to the elbow in the trap. Cut
the pipe so that it extends through the
alternate drain hole in the left side of
the cabinet one inch (see Figure 34).
1
Connect the / " PVC tee (supplied
2
with the furnace) to the pipe with a 1-
3/4" riser.
38
IMPORTANT: Do not connect into a
common drain line with an air
conditioner evaporator coil drain
located above the furnace. A blocked
or restricted drain line can result in
overflow of the coil pan and negate
the furnace blocked-drain shutoff
control.
FILLING THE TRAP
FILL THE TRAP ASSEMBLY WITH
WATER BEFORE OPERATING THE
FURNACE. Do this by removing the
drain hose from the trap or from the
connection to the secondary coil.
Pour about a cup of water into the
vent trap. Any excess water flows into
the house drain when the trap is full.