Rheem RTGH-3 Series Installation Instructions Manual

INSTALLATION INSTRUCTIONS
Water Piping Arrangement With Service Valve Kit
Service valve kits can attach to all tankless
water heater systems. All kits include two full-
port isolation valves to be used in the COLD
and HOT water lines. When installed, these
valves allow one person full diagnostic testing
and ease of flushing the system. Contact your
distributor or place of purchase for availability
and installation information.
Water Supply (cont.)
Relief Valve
A new pressure-relief valve, complying with the
Standard for Relief Valves and Automatic Gas
Shut-Off Devices for Hot Water Supply Systems,
ANSI Z21.22/CSA 4.4, must be installed at the HOT
water outlet connection of the water heater during
installation. Local codes shall govern the installation
of any relief valve.
NOTICE:
• The following drawing illustrates a pressure-only relief
valve. If local codes require a combination temperature
and pressure-relief valve, you may need to install an
extension piece to ensure that the valve probe is not
directly in the flow path of the water.
• A pressure relief valve supplied with this water heater must
be installed as shown below.
• Manual operation of relief valves should be performed at
least once a year.
• If the relief valve on the system discharges periodically, a
problem exists. Turn off the water heater, unplug the unit,
and call for service.
One end of the relief valve discharge line connects
to the HOT water outlet pipe as shown above. The
other end of the pipe should be routed to a suitable
drain to eliminate potential water damage.
Relief
Valve
Union Union
Hot Water
Supply Outlet
40
For safe operation of the water heater, be sure that:
The pressure rating of the relief valve must not
exceed 150 psi (1,034 kPa) or the maximum working
pressure of the water heater. (See the rating plate on
the water heater.)
The BTUH rating of the relief valve must equal or
exceed the BTUH input of the water heater. (See the
rating plate on the water heater.)
No valve of any type should be installed between the
relief valve and the water heater.
Discharge from the relief valve should be piped to
a suitable drain. Piping used should be of a type
approved for the distribution of hot water.
HOT and COLD water lines should be insulated up to
the water heater. See "Water Supply Installation".
The discharge line must be NO SMALLER than the
outlet of the relief valve. The drain line must pitch
downward to allow for complete drainage of the line
and the valve.
The end of the discharge line should not be threaded
or concealed and should be protected from freezing.
No valve of any type, restriction, or reducer coupling
should be installed in the discharge line.
Cold Water Supply
Cold Water
Supply Inlet
Relief Valve
Discharge Line
Pressure Pressure
Relief Valve Relief Valve
Hot Water Hot Water
Service Valve Service Valve
Water
Water
Outlet Outlet
Drain
Drain
Cold Water
Cold Water
Service Valve Service Valve
Water Water
Inlet Inlet