Listed
Cap
Listed Gas
Vent
H (minimum) - Minimum height from
roof to lowest discharge opening
Lowest discharge opening
Roof pitch is x/12
1. If connected, turn pump, main gas valve, and heater
power off.
2. Locate the heater as close as practical to the gas vent
exit.
3. Remove the countersunk phillips-head screws and
remove the flue cover panel on top of the heater and
discard. Save the countersunk screws as they will be
re-used later.
4. Remove the screws that fasten the heat barrier to the
heater. Remove the heat barrier and discard. See
Figure 3.
5. Remove the screws that fasten the rain guard to the
heater. Remove the rain guard and discard. See
Figure 3.
6. Install the vent pipe adapter plate included in this kit
into the heater using the #10 screws included with this
kit. Ensure the white gaskets are in place under the
vent pipe adapter plate before installing. See Figure 4.
7. Install the new flue cover included with this kit over the
vent pipe adapter and secure with the countersunk
screws from step 3 above. See Figure 5.
8. Remove heater front access door.
9. Install the vent pressure switch provided with this kit
inside the heater using 2 #10 screws as shown in
Figure 6. If you are refitting a heater with an
FDXLRGK1xxx kit, you will need to drill these screw
holes.
10. Remove the rubber cap from the blower outlet
pressure tap and discard. See Figure 7 for blower tap
location.
11. Attach the pressure switch tubing to the pressure tap
on the blower outlet. See Figure 7 for blower tap
location. On some older model heaters, the pressure
tap is located on the opposite side of the blower
housing as shown in Figure 7.
12. Unplug the in-line quick connect on the red wire in the
heater wire harness and attach the 2 wires to the vent
pressure switch. See Figure 6. If you are refitting a
heater with an FDXLRGK1xxx kit, you will need to
splice into the wire harness red wire which attaches to
the water pressure switch. The vent pressure switch
should be in series with the water pressure switch.
1301666601 rev B
INSTALLATION PROCEDURE
Page 4 of 10
Vent Termination
Vent extending through a roof or wall must be listed
double-wall (Type B) vent, and pass through an approved
roof jack, or roof thimble. A listed vent cap must be used.
Gas vents that are spaced less than 8 ft horizontally from
a vertical wall or similar obstruction shall terminate not less
than 2 ft above any portion of a building within 10 ft. Gas
vents that are spaced 8 ft or more horizontally from a
vertical wall or similar obstruction shall terminate above
the roof a distance
H
based on the roof pitch. Using the
roof pitch, find the minimum value of
H
using Figure 2 and
Table 6.
NOTES ON INDOOR INSTALLATIONS (continued)
TABLE 6
Roof Slope
Min. Height H from
Roof to Lowest
Discharge Opening
Flat to 6/12
1.0 ft
Over 6/12 to 7/12
1.25 ft
Over 7/12 to 8/12
1.5 ft
Over 8/12 to 9/12
2.0 ft
Over 9/12 to 10/12
2.5 ft
Over 10/12 to 11/12
3.25 ft
Over 11/12 to 12/12
4.0 ft
Over 12/12 to 14/12
5.0 ft
Over 14/12 to 16/12
6.0 ft
Over 16/12 to 18/12
7.0 ft
Over 18/12 to 20/12
7.5 ft
Over 20/12 to 21/12
8.0 ft
FIGURE 2
13. If installing the kit on models H250FDN,
H250FDP, or H400FDP, you must also replace
the existing blower air inlet restrictor with the
new one included in the kit.
a) Remove the 4 #10 hex head screws that
fasten the plate to the blower, and remove
the blower air plate and discard. Save the
4 screws as they will be needed to install
the new plate.
EN
G
LIS
H
b) Install the new blower plate included in the kit
using the 4 screws. It may be helpful to drive the
screws in and out of the plate outside of the
heater first to "thread" the holes before installing it
in the heater. See Figure 7.
14. Re-install heater front door.
15. Connect vent piping system to heater vent adapter.
16. If connected, turn pump, main gas valve, and heater
power back on.
17. Activate heater and check for proper function.
