Rheem HP50RH Thermal Expansion, Water Supply Connections, Condensate Drains for the Heat Pump

Installing the water heater.

Thermal Expansion

Determine if a check valve exists in the inlet water line. Check with your local water utility. It may have been installed in the cold water line as a separate back flow preventer, or it may be part of a pressure reducing valve, water meter or water softener. A check valve located in the cold water inlet line can cause what is referred to as a “closed water system”. A cold water inlet line with no check valve or back flow prevention device is referred to as an “open” water system.

As water is heated, it expands in volume and creates an increase in the pressure within the water system. This action is referred to as “thermal expansion”. In an “open” water system, expanding water which exceeds the capacity of the water heater flows back into the city main where the pressure is easily dissipated.

A “closed water system”, however, prevents the expanding water from flowing back into the main supply line, and the result of “thermal expansion” can create a rapid and dangerous pressure increase in the water heater and system

piping. This rapid pressure increase can quickly reach the safety setting of the relief valve, causing it to operate during each heating cycle. Thermal expansion, and the resulting rapid and repeated expansion and contraction of components in the water heater and piping system can cause premature failure of the relief valve, and possibly the heater itself. Replacing the relief valve will not correct the problem!

The suggested method of controlling thermal expansion is to install an expansion tank in the cold water line between the water heater and the check valve (refer

to the illustration on the next page). The expansion tank is designed with an air cushion built in that compresses as the system pressure increases, thereby relieving the over pressure condition and eliminating the repeated operation of the relief valve. Other methods of controlling thermal expansion are also available. Contact your installing contractor, water supplier or plumbing inspector for additional information regarding this subject.

Water Supply Connections

Refer to the illustration on the next page for suggested typical installation. The installation of unions or flexible copper connectors is recommended on the hot and cold water connections so that the water heater may be easily disconnected for servicing if necessary. The HOT and COLD water connections are clearly marked and are 3/4″ NPT on all models. Install a shut-off valve in the cold water line near the water

heater. See page 8 on "To Fill The Water

Heater".

NOTICE: Do not apply heat to the hot or cold water connections. If sweat connections are used, sweat tubing to adapter before fitting adapter to the water connections on heater. Any heat applied to the water supply fittings will permanently damage the dip tube and/or heat traps.

Condensate Drains for the Heat Pump

Consult local codes or ordinances for specific requirements. Refer to page 7.

IMPORTANT: When making drain fitting connections to the drain tubing, use a thin layer of piping tape or silicone and install hand tight.

IMPORTANT: When making drain fitting connections to the drain tubing, DO NOT overtighten. Overtightening fittings can split pipe connections on the drain pan.

•Do not reduce drain line size less than connection size provided on condensate drain.

•All drain lines must be pitched

downward away from the unit a minimum of 1/8" per foot of line to ensure proper drainage.

•Do not connect condensate drain line to a closed or open sewer pipe. Do not allow condensate to drain into the water heater drain pan.

•The drain line should be insulated where necessary to prevent sweating and damage due to condensate forming on the outside surface of the line.

•This unit is equipped with a 3/4" primary condensate connection and a 1/2" overflow connection.

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