Rheem RS47-21BP Use & Care Manual page 22

Installing the water heater.
Frame Installation continued....
NOTICE: Allow
room for "U" bracket
pipe leg cradle on
frame. Roofs with
steep pitches (above
20°) may require
short pipe legs at
collector end of frame
for clearance.
22
• Drill each runner in center and 6" from
runner ends and screw to rafters or
trusses with 5/16" x 6" lag screws and
washers,
• Flash and seal all roof penetrations.
3. Move all pieces of Frame to roof and
assemble (refer to Figure below).
4. Attach Frame to runners:
For shallow-pitch or flat roofs, screw
frame directly to runners.
For side pitch or reverse pitch roofs;
• Loosely screw collector end of frame to
runners with 5/16" x 1 3/4" lag screws
and washers,
• Level frame and measure the required
length for the tank-end pipe legs ( 5),
• Measure and cut un-drilled end of pipe
Frame Assembly
Pipe Leg Connection Detail
2"
Frame
Screws
Leg
"U"
Bracket
legs to correct length,
• Attach 'U' brackets to runners with
5/16" X 1 3/4" lag screws and washers
or Unistrut bolts (refer to Figure
below),
Lower Pipe Leg Installation
• Insert un-drilled ends of pipe legs into
frame,
• Attach drilled end of pipe legs to 'U'
brackets using 2" screws,
• Screw pipe legs to frame with 2"
screws through pipe legs and frame
sleeves,
•Continue with Collector Installation.