International Thermal Research
8-1
Domestic Hot Water Heating
Engine Heat Management
8.1 Before You Begin
When the heater is used only for heating domestic water and
space heating is not required, a three-way valve or electric
solenoid can be installed. This valve is intended to divert the
heat transfer fluid through the heat exchanger but not the
space heating loop Refer to Fig. 8-1. The selector valve
should be mounted so it is easy to reach. See Figure 6-4 for
details of the electrical connections for a solenoid.
Also, the heat exchanger has another heat transfer loop.
Heat can be transferred from the heater to the engine for
supplemental heat for engine pre-heat during cold weather.
For help with wiring the electrical components of the heat
exchanger, refer to Figure 6-4 wiring schematic in Section 6,
Wiring the Electrical System.
8.2 Domestic Hot Water System
The components needed for installation and operation of the
domestic hot water system include:
Heat exchanger — The stainless-steel flat plate heat
exchanger is UL and CSA approved for domestic water
heating. This is installed inside the Oasis® Zephyr™ HW for
hot water output once the heater reaches its cycle-off
temperature (approx. 180ºF).
Aquastat — An aquastat (temperature sensor) signals the
burner to fire and maintain system cycling temperature when
there is a call for hot water.
Thermostatic tempering valve — For temperature control
and to prevent scalding since the domestic water could reach
180°F (82°C). This is pre-set at the factory at 120°F.
Section
8
A heat exchanger is
located inside the
Oasis® Zephyr™
HW to provide
continuous hot
water once the
cycling temperature
of the heater has
been reached. The
burner must be
operating in order to
supply hot water.
