Installation Manual

18
WHL-019 REV. 12.17.14
EXPANSION TANK AND MAKE-UP WATER
1. Ensure that the expansion tank is sized to correctly handle heater and system water volume and temperature.
Undersized expansion tanks cause system water to be lost from the relief valve, causing make-up water to be added. Eventual heater
failure can result due to excessive make-up water addition. SUCH FAILURE IS NOT COVERED BY WARRANTY.
2. The expansion tank must be located as shown in the Heater Piping Details, or following recognized design methods. See expansion
tank manufacturer’s instructions for details.
The expansion tank must be suitable for hot potable water.
F. WATER PIPING
Never use dielectric unions or galvanized steel fittings on any domestic water or auxiliary connections. Use only copper or brass fittings.
Thread sealant must be used on all connections.
The domestic water connections must be installed in accordance to all local and national plumbing codes, or any applicable standard
which prevails. The inlet and outlet ports are 1" on 55 gallon models, and 1 ½” on 80 and 119 gallon models.
On the cold inlet, install a 1" brass tee on 55 gallon models, or a 1 ½" tee on 80 and 119 gallon models. On the run of the 1" brass tee,
install a 1" brass drain cock or equivalent with pipe sealant compound. In the branch of the 1" or a 1 ½" brass tee, install a copper male
adapter to match your copper plumbing system. For convenience, you may install a sweat shut off valve and a union in the cold inlet
piping to ease future servicing. If there is a back flow preventer or any type of a no return valve in the system, you must install an
additional tee here, suitable for a potable hot water expansion tank.
In the hot outlet, install a suitable adapter to match the copper tubing of the plumbing system. A thermal trap or heat trap loop may be
installed here to provide additional energy savings and prevent the thermal siphoning of domestic hot water.
G. AUXILIARY CONNECTIONS
The auxiliary connections are additional connections for air handlers, plate exchangers, or other devices that supply hot water. These
connections must be installed in accordance with all local and national codes or any applicable standard that prevails. Auxiliary
connections are 1" on all models. Never use dielectric unions or galvanized steel fittings. Use only copper or brass fittings. Sealant must
be used on all connections. The top port is the supply outlet and the bottom port is the return inlet.
Never connect auxiliary connections to any system that uses glycol or other solutions formulated for hydronic systems. These auxiliary
connections are to be used only in a potable water system. Failure to follow this warning could result in serious injury or death.