Operating instructions

Fig. 401: Series Plumbing Circuit (Shown with heater installed)
B: Heater Cores arranged in Parallel (fig. 402)
A parallel heating system works in this fashion:
Heated water (coolant) from the engine travels through a common
supply and return circuit, but unlike a series system, the heater cores
are connected across the circuit at intervals along its length.
Each core shares the available coolant and heat equally, resulting in
increased heating efficiency and decreased coolant restriction.
Fig. 402: Parallel Plumbing Circuit (Shown with heater installed)
A fuel fired Webasto heater used in conjunction with a high capacity
coolant pump can significantly increase the available heat and coolant
volume supplied to both series and parallel systems increasing interior
heating efficiency. With the addition of a timer, the above systems can
also provide pre-heating capability.
CAUTION
A path for coolant to flow
must be provided
whenever the Webasto
heater is operating.
CAUTION
Water pump(s) must be
operating when the
Webasto heater is in
operation..
4 Installation Thermo 230/300
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