Rheem RTGH-RH11DV Use And Care Manual page 47

Standard Mode
1. Only POTABLE water may be plumbed through the water heater.
2. The water heater cannot be used for space heating applications.
3. Expansion tank is required if a backflow preventer is installed.
4. Isolation valve kits are recommended for this installation.
Figure 25 – Standard Mode Piping, Single Water Heater
External Recirculation mode
The recirculation pipe must be installed in the field in
order to use 'External Recirculation Mode'.
This mode allows the water heater to recirculate
heated water through the system and additionally
serves as a freeze protection function.
When using external recirculation mode with the
built-in pump, check the following maximum recir-
culation pipe lengths including fittings (3/4" pipe is
recommended):
-1/2" Pipe- 200' (60m) of equivalent length
-3/4" Pipe- 500' (150m) of equivalent length Lengths
in excess of these limits will require an external
recirculation pump.
Figure 26 – Piping with External Recirculation Mode
NOTE: These drawings are meant to show system piping concept only. Installer is responsible for all equipment and detailing required
by local codes.
Air & Gas
Mixing
Burner
Primary heat
exchanger
Secondary heat
exchanger
Recirculation
Pump
Pressure Relief Valve
Secondary heat
Recirculation
Pump
Pressure Relief Valve
Gas
Backflow Preventer
(optional)
Expansion Tank (Install
according to local code)
Air & Gas
Mixing
Burner
Primary heat
exchanger
exchanger
Gas
Expansion Tank (Install
according to local code)
AP18733 REV. 3.2.17
47