8 | General information
Internal wiring schematic for single phase WH27 unit.
How the water heater works:
The Tronic 6000C heats water continuously as it flows
through the 2 heater modules.
The electronic control PCB monitors the flow rate and the
incoming water temperature and then switches on the
required number of heater elements to reach the
temperature set by the temperature adjustment dial.
The temperature dial sets the heater set-point
temperature. Please note heat loss, pipe run, and other
factors affect the outlet temperature at end use.
As the flow rate or the incoming water temperature
changes, the electronic control adjusts the number of
heater elements used so that the outlet temperature is
The outlet water temperature can change slightly as the
flow rate changes due to the steps in power as different
heater elements are switched on and off.
The outlet water temperature can also vary if the maximum
flow rate is exceeded (see Fig. 11) or if the supply
6 720 646 951 (2015/04)
Each heater module is protected by an electro-mechanical
thermal cut-out. This cut-out will only trip in exceptional
Contact Technical Support 800-798-8161 for further
The WH17 unit is supplied from two independent voltage
supplies and the WH27 unit from three independent
voltage supplies. (In Canada the unit has just one voltage
Depending on the region of the country, the temperature of
the water supply can vary between an average of 40 °F in
winter to 70 °F in summer, with an average of 55 °F. The
output temperature and maximum flow of the heater is
dependent on inlet water temperature.