LAARS Mighty-Stack TL00-199 - Installation, Operation and Maintenance Instructions - Manual (Page 10)

LAARS HEATING SYSTEMS Page 10
Figure 9. Horizontal Vent Terminations.
2. If a backflow preventer, pressure reducing valve,
or check valve is included in the cold water
supply line, you must provide a way to control
thermal expansion of the water in the tank. This
will prevent the temperature and pressure relief
valve from being forced open repeatedly. For
advice on controlling this situation, contact the
water supplier or local plumbing inspector.
Install an expansion tank of the proper size, as
shown in Figure 10.
3. The discharge piping for the pressure relief valve
must be directed so that the hot water cannot
splash on anyone. Attach the run-off tube to the
pressure relief valve, and run the end of the tube
to within 6" (152 mm) of the floor. Do not install
any reducing couplings, valves, or any other type
of restriction in this line. This run-off tube must
be installed to allow free and complete drainage
of both the valve and the run-off tube.
WARNING
Don’t install the run-off tube so the end terminates
outdoors. This could allow a freezing condition to
plug the end of the pipe. If the run-off tube is
allowed to remain blocked, an explosion may result.
This can cause property damage, personal injury,
or death.
NOTE: Ensure expansion tank pressure rating is
sufficient to withstand system operational pressure.
Figure 10. Expansion Tank Installation.
1N. Electrical Wiring
1. Check the voltage, frequency, and phase of the
wiring to the water heater. This unit is designed to
operate on 115V AC, 60 Hz, single phase. (The
controls and switches on this unit operate on 24V
AC. This voltage is produced by a transformer
and draws less than 12A.)
2. A means of switching off 115V AC to the unit is
provided by a 3 position toggle switch on the
control panel. Additional switches or
connections may be required by local authority.
If there are no local requirements, follow the
latest edition of the National Electrical Code,
ANSI/NFPA 70 in the U.S. In Canada, follow
the latest edition of CSA C22.1 Canadian
Electrical Code, Part 1.