Instructions / Assembly
14
4. Remove as much built-up scale from flue tubes and tank bottom
as practical. Do not attempt to clean so thoroughly that the tool
used damages the glass lining.
5. Clean the seal plate and install a new gasket. Wipe clean the
interior surface of the tank that contacts the gasket. Reinstall
the seal plate and tighten in position. Fill tank with water and
check for leaks. If no leaks are found, install insulation plug and
clean-out cover on jacket and re-light the water heater.
If chemical lime dissolving cleaners are preferred, cautiously follow
the instructions supplied with the cleaner. DO NOT use a muriatic
or hydrochloric acid (HCl) base cleaner.
2. ANODE INSPECTION — The water supply in cer tain areas
contains very aggressive elements. In these areas, periodic inspec-
tion of the anode is recommended to determine if replacement is
necessary. The anode(s) supplied in this water heater is slowly
consumed , thereby eliminating or minimizing corrosion and pro-
tecting the glass lined tank. The anode(s) should be replaced when
more than 6 inches (15 cm) of core wire is exposed at either end.
3. SEASONAL OPERATION — If the water heater is to remain
idle for an extended period (60 days or more) the heater should be
turned off. The water heater and piping should be drained if they
might be subjected to freezing temperatures. It is recommended
that the water heater’s operation is thoroughly checked (by a quali-
fied service technician) before it is placed back in service. NOTE:
TABLE 1
Maximum Capacity of Pipe in Cubic Feet of Gas per Hour for Gas Pressures of
--------0.5 psig or Less and a Pressure Drop of 0.3 Inch Water Column
Based on a 0.60 Specific Gravity Natural Gas; If 1.5 Specific Gravity L.P. Gas is used, multiply capacity by 0.63
Nominal Internal
Iron Pipe Size, Diameter
Inches Inches 10 20 30 40 50 60 70 80 90 100 125 150 175 200
1/2 .622 132 92 73 63 56 50 46 43 40 38 34 31 28 26
3/4 .824 278 190 152 130 115 105 96 90 84 79 72 64 59 55
1 1.049 520 350 285 245 215 195 180 170 160 150 130 120 110 100
1 1/4 1.380 1,050 730 590 500 440 400 370 350 320 305 275 250 225 210
1 1/2 1.610 1,600 1,100 890 760 670 610 560 530 490 460 410 380 350 320
2 2.067 3,050 2,100 1,650 1,450 1,270 1,150 1,050 990 930 870 780 710 650 610
2 1/2 2.469 4,800 3,300 2,700 2,300 2,000 1,850 1,700 1,600 1,500 1,400 1,250 1,130 1,050 980
3 3.068 8,500 5,900 4,700 4,100 3,600 3,250 3,000 2,800 2,600 2,500 2,200 2,000 1,850 1,700
4 4.026 17,500 12,000 9,700 8,300 7,400 6,800 6,200 5,800 5,400 5,100 4,500 4,100 3,800 3,500
Length of Pipe, Feet
Maintenance
To Remove Burner(s):
1. Turn off gas and electric unit. Remove the nine (9) screws
that hold the plenum back cover. Remove cover and set to
the side.
2. Disconnect the main gas line from the inlet of the gas valve.
Remove the four (4) screws that hold the gas manifold, then
remove the two (2) screws that hold the plate on the other
end of the gas manifold.
3. To remove the manifold, it will need to slide back away from
the unit, to allow the orifices to clear the end of the burners,
then slide out of the plenum (mounting plate can be left in
the plenum).
4. To remove a burner, remove the four (4) screws that hold it
in place. Slowly pull the burner out of the mounting plate.
5. Inspect the burner and replace if there is damage to the port
area. The re-install a burner in the mounting plate. Push
burner slowly into the mounting plate opening.
6. Reverse Steps 2 through 4, to install any burner(s) removed
from the unit. Make sure all mounting screws are tight. Then
turn on gas and electric.
To Remove Pilot Assembly:
1. Refer to Steps 1 through 3 to the left, to start the pilot as-
sembly removal.
2. Disconnect the pilot tube from the gas valve and then remove
the grommet from the plenum side. Carefully push the tube
through the hole in the plenum side, while holding the other
end (closest to the pilot).
3. Remove the two (2) screws from the pilot assembly. Rotate
pilot assembly (down and clockwise) to remove from burner
mounting plate. See page 12 for better view of screws.
4. Reverse above steps to install new pilot assembly. Make
sure that all gas connections are tight and all screws are
re-assembled and tightened (do not over tighten screws).
Burner and pilot assembly removal instructions specific to GNU models
Manifold Plate
Screws (2)
Blower Assembly
Grommet for
pilot tube
Gas Manifold
Pilot
Assembly
Burner
Screws