10
Installation Instructions
8.
Water Piping
This appliance is suitable for potable water applications. Do not use this appliance if any part has been underwater.
Immediately call a qualified service technician to inspect the appliance and replace any part of the control system and
gas control which has been under water.
Piping and components connected to the water heater shall be suitable for use with potable water.
Toxic chemicals, such as those used for boiler treatment, shall not be introduced into the potable water.
A water heater used to supply potable water may not be connected to any heating system or components previously
used with a nonpotable water heating appliance.
When water is required in one part of the system at a higher temperature than in the rest of the system, means such
as a mixing valve shall be installed to temper the water to reduce the scald hazard.
Installation and service must be performed
by a qualified plumber.
Observe all applicable codes.
• Flush water through the pipe to clean out metal powder, sand and dirt before connecting it.
• Perform the following insulation measures for prevention of freezing.
• Take appropriate heat insulation measures (e.g., wrapping with heat
insulation materials, using electric heaters) according to the climate of
the region to prevent the pipe from freezing.
• Make sure that there are no water leaks from the cold and hot water
supply pipes, then insulate the pipes completely.
• Be sure to also completely insulate the water supply valve and the
cold and hot water connections on the water heater (refer to the figure
on the right).
• Do not cover the water drain plug with insulation so that water in the
pipe can be drained. (Refer to the figure in the right.)
• Use a union coupling for connecting the pipes to reduce the force applied to the piping.
• When feed water pressure is too high, insert a depressurizing valve, or take water hammer prevention measure.
• Avoid using joints as much as possible to keep the piping simple.
• Avoid piping in which an air lock can occur.
• Use approved piping materials.
• If installing the unit on a roof (Above lower-level hot water supply):
If the unit is installed on a roof to supply water to the levels below, make sure that the water pressure supplied to
the unit does not drop below 199 kPa. It may be necessary to install a pump system to ensure that the water
pressure is maintained at this level.
Check the pressure before putting the unit into operation.
Failure to supply the proper pressure to the unit may result in noisy operation, shorter lifetime of the unit, and may
cause the unit to shut down frequently.
Completely insulate
the water inlet and
outlet fittings.
Insulate the water
supply valve completely.
Do not cover the water
drain plug with insulation
so that water in the pipe
can be drained.
