RDG603A8 - Issue 1 - Shire 14 Canal Boat Complete Manual 30, 35, 38, 40, 45, 50.doc
Page 29 of 50
Figure 4-1: Twin Thermostat Operation
With the engine quickly up to operating
temperature, the first 71° thermostat
opens. The water now flows to the
domestic hot water tank, resulting in
hot water being rapidly available.
When the water stored in the hot water
tank has reached full temperature, the
second 88° thermostat opens and
water can then flow to the skin tank
and correctly control engine cooling.
The exhaust manifold that earlier
helped to heat engine water is now
cooled to ensure safe operation and
reduce engine compartment
temperatures.
If the load on the engine reduces and
the demand for domestic hot water
increases then the system will
automatically compensate and re-
direct water to ensure that a plentiful
supply of hot water is always available.
