Rheem Raypak R207A - Unitherm Governor Operation; Internal Automatic Bypass Valve

17
This component provides protection to the heat exchanger
against galvanic corrosion, when properly bonded to the
heat exchanger. It should be replaced when the weight of
the ProTek Shield is reduced to about 40% of the original
weight (1.46 #).
F10715
Figure 20. ProTek Shield Assy
AA
CAUTION: STOP pool pump before attempting to
remove ProTek Shield Assembly. Failure to do so may
result in damage to ProTek Shield Assy, loss of pool
water, or personal injury.
CAUTION: Do not use tools to remove (twist) the
ProTek Shield Assy or the wing nut on the stud of the
ProTek Shield Assy. Non-warrantable damage may
occur.
Follow the steps below to replace the ProTek Shield Assy:
1. Shut off the pool pump and bleed pressure from the
system.
2. Close isolation valves to minimize pool/spa water
loss.
3. Remove wing nut from bottom stud on ProTek Shield
Assy.
4. Remove bonding wire ring terminal from stud.
5. Rotate ProTek Shield Assy clockwise (by hand) to
unscrew it from the assembly.
6. Inspect/replace as necessary and reverse above
procedure to reinstall. Hand tighten only! Do not use
tools.
NOTE: Make sure the O-ring is properly seated in the
O-ring groove before installation.
Unitherm Governor Operation
AA
CAUTION: The patented Unitherm Governor is
a thermostatic mixing valve specically designed to
maintain constant heater internal temperature between
105°F (41°C) and 115°F (46°C) despite continually
changing ow rates from the lter and changing pool
temperatures. This narrow range is needed to prevent
damaging condensation on the burners which will
occur if the heater runs for any length of time below
100°F (38°C). It is also needed to inhibit scale formation
in the tubes by maintaining temperatures well below
accelerated scaling temperatures.
F10725
GASKET
UG PLUG
UNITHERM GOVERNOR
Figure 21. Unitherm Governor – Polymer
F10642-2
UG/BYPASS ASSY
UNITHERM
GOVERNOR
Figure 22. Unitherm Governor – Brass
Internal Automatic Bypass Valve
In addition to the Unitherm Governor, a built-in automatic
bypass valve is provided in the In/Out header. While the
Unitherm Governor responds to the changes in water
temperature in the heater, the internal bypass valve
automatically responds to changes in water pressure in the
piping system. Proper amount of water ow is maintained
through the heater under varying pressures dictated by the
conditions of the pump and lter.
F10642-1
UG/BYPASS ASSY
BYPASS DISC
SPRING
"RED" - 206/266
"SILVER" - 336/406
Figure 23. Internal Automatic Bypass Valve ASME
NOTE: The Unitherm Governor and Bypass Valve Assy
are not individually replaced components on ASME
units. If either needs to be replaced, the entire UG/
Bypass assy must be replaced. The "red" spring is used
on models 206/266 and the "silver" spring is used on
models 336/406.
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