Water Piping - Rheem Raypa DELTA 399B Installation And Operation Manual

of not less than 1 in.
per kW) of total rated input of the burner(s), and
the location of the opening(s) shall not interfere
with the intended purpose of the opening(s) for
ventilation air referred to in (1). This opening(s)
can be ducted to a point not more than 18 in. (450
mm) nor less than 6 in. (152 mm) above the floor
level. The duct can also "goose neck" through the
roof. The duct is preferred to be straight down 18
in. (450 mm) from the floor, but not near piping.
4. Refer to B149 Installation code for additional infor-
mation.

Water Piping

General
The heater should be located so that any water leaks
will not cause damage to the adjacent area or struc-
tures.
ACAUTION: This heater requires forced water
circulation when the burner is operating. See
Table G and Table H for minimum and maximum
flow rates and water pump selection. The pump
must be interlocked with the heater to prevent
heater operation without water circulation.
NOTE: Minimum pipe size for in/out connections
is 2 ⁄ in (2 in. for 399B–899B). Verify proper flow
1
2
rates and ∆T as instructed in this manual.
Reversing Water Connections
Follow these instructions to change the water connec-
tions from the left-hand side (standard) to the right-
hand side.
1. Disconnect all electrical power from the heater (if
applicable).
2. Label all electrical connections and conduit lines.
This may include the flow switch, low water cut-off
probe and/or pump.
3. Disconnect or isolate the main gas pipe from the
heater (if applicable).
4. Remove both in/out and return header access
panels by removing all sheet metal screws.
14
for each 30,000 BTUH mm
2
5. Remove all plumbing fittings to the header. This
2
will include both inlet and outlet water pipe unions
and the pressure relief valve and drain piping.
6. Remove limits, control bulbs and/or thermocou-
ples.
7. Remove the six (or 8) flange nuts and the in/out
header from the left-hand side.
8. Remove the six (or 8) flange nuts and the return
header from the right-hand side.
9. Remove the header stud bolts from each tube
sheet.
10. Reverse the headers and stud bolts to the new lo-
cation.
11. Install NEW red beveled O-rings flush against both
tube sheets with the bevel facing outward.
12. Push the header firmly against the O-rings. Install
and tighten the flange nuts onto the stud bolts until
finger tight.
13. Slowly tighten the flange nuts, starting from the
center nut (number 1) in Fig. 9 and working se-
quentially around the header as indicated. Torque
all nuts to 25 ft/lb. DO NOT OVER-TIGHTEN.
14. Re-route the capillary(s), wiring etc. to the new lo-
cation, adding thermal paste and shim to the capil-
lary well.
Relief Valve Piping
WWARNING: Pressure relief valve discharge
piping must be piped near the floor and close to
a drain to eliminate the potential of severe burns.
Do not pipe to any area where freezing could oc-
cur. Refer to local codes.