HTP PHE199-119 - Manual (Page 16)

16
LP-314 REV. 3.24.14
PART 4 - DOMESTIC WATER PIPING
Failure to follow the instructions in this section WILL VOID the warranty and may result in property damage, serious injury, or death.
DO NOT pipe this water heater with black iron, galvanized steel, steel, or lead pipe. Doing so will result in premature product failure and
property damage, and WILL VOID the product warranty.
A. TEMPERATURE AND PRESSURE RELIEF VALVE FOR DHW
Install a temperature and pressure relief valve into the marked port (upper right). We recommend a WATTS 40XL5 valve or equivalent
for 130,000 BTU models or above input. The valve must meet the ANSI Z21.22B requirements for relief valves for hot water heaters as
per a nationally recognized lab that maintains a periodic inspection of production of such listed safety device. The pressure rating of the
valve must not exceed the listed working pressure of this appliance, and must be rated to the proper BTU/hr capacity of the appliance.
To avoid water damage or scalding due to relief valve operation:

Discharge line must be connected to relief valve outlet and run to a safe place of disposal. Terminate the discharge line in a
manner that will prevent possibility of severe burns or property damage should the relief valve discharge.

Discharge line must be as short as possible and the same size as the valve discharge connection throughout its entire length.
 Discharge line must pitch downward from the valve and terminate at least 6” above the floor drain, making discharge clearly
visible.

The discharge line shall terminate plain, not threaded, with a material serviceable for temperatures of 375
o
F or greater.

Do not pipe discharge to any location where freezing could occur.

No shutoff valve may be installed between the relief valve and heater or in the discharge line. Do not plug or place any
obstruction in the discharge line.

Test the operation of the relief valve after filling and pressurizing the system by lifting the lever. Make sure the valve
discharges freely. If the valve fails to operate correctly, immediately replace with a new properly rated relief valve.

Test T&P valve at least onc e annually to ensure the waterway is clear. If valve does not operate, turn the heater “off” and call
a plumber immediately.

Take care whenever operating relief valve to avoid scalding injury or property damage.
FAILURE TO COMPLY WITH THE ABOVE GUIDELINES COULD RESULT IN FAILURE OF RELIEF VALVE OPERATION,
RESULTING IN POSSIBILITY OF SUBSTANTIAL PROPERTY DAMAGE, SEVERE PERSONAL INJURY, OR DEATH.
Do not, under any circumstances, thread a cap or plug into the relief valve! Explosion, serious injury or death may result. Relief valve
piping must be directed to the floor or an open drain, but not connected.
There must be a 6" space between the outlet of relief valve piping and drain or floor. Do not hook up to drain system directly without an
air space. The relief valve must be checked periodically for proper operation.
B. DOMESTIC HOT WATER EXPANSION TANK
A potable hot water expansion tank is required to offset the expansion as the water is heated. In most city plumbing systems, the water
meter has a no return or back flow device built into the system to prevent water flowing back into city mains. Some local codes require
back flow preventers on all incoming water supplies. The hot water expansion tank must be listed for potable water use. The expansion
tank should be located on the cold inlet piping close to the appliance.
The expansion tank must be suitable for hot potable water.