Installation instructions
3.9Water connections
Warning: This heater must be supplied with cold potable water. It is not
approved for preheated water applications. See chapter 3.12 for approved recirculating application.
Warning: In areas where the water supply has a high mineral content, a water softener is strongly recommended. Damage to the water heater resulting from hard water/scale deposits will not be covered under warranty.
BWhen facing the heater, the ¾” cold inlet connection is on the bottom right and the hot connection is on the bottom left. Centrally locating the water heater is recommended to keep hot water distribution times even throughout the structure.
INLET
FILTER
UNION
(not sup-
plied with 
heater)
HOTCOLD
Fig. 25
BThe use of unions when connecting both water pipes to the cold and hot water connections is required. This will facilitate any necessary servicing.
BPlastic or PEX type plumbing line materials are not suitable for connecting directly to the water heater.
BAlthough water piping throughout the building may be other than copper, we recommend that copper or suitably rated stainless steel flex line piping be used for the water connections for 1.5’ on either side of the water heater (follow local codes if more strin- gent).
BNever sweat any rigid piping directly to or beneath the water connections, as damage can occur to the internal water valve from heating of the pipe.
BKeep water inlet and outlet pipes to no less than ¾" (19.05mm) diameter to allow the full flow capacity.
B If the cold and hot connections to the heater are reversed, the heater will not function. Be certain there are no loose particles or dirt in the piping. Blow out
or flush the lines before connecting to the water heater.
BFull port shutoff valves should be installed on both the cold water supply and hot water outlet lines to facilitate servicing the heater (see Fig. 26).
Note: If water flow or pressure is low, or heater does not ignite, check the water inlet filter screen for debris (see Chapter 5.1).
Connecting the pressure relief valve (PRV)
A listed pressure relief valve supplied with the heater must be installed at the time of installation. No valve is to be placed between the PRV and the heater. No reducing coupling or other restriction may be installed in the discharge line. The discharge line must be a minimum of 4” above a drain and installed such that it allows complete drainage of both the PRV and the line. The location of the PRV must be readily accessible for servicing or replacement, and be mounted as close to the water heater as possible. See Fig. 26. To install the PRV, a suitable fitting connected to an extension on a “T” fitting can be sweated to the hot water line.
Support all piping.
Fig. 26 Plumbing connections (with isolation valves) and pressure relief valve
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