Product Manual

3.10.1 Coolant liquid circuit “inline integration”

Cut the water flow hose from the vehicle engine to the vehicle's
heat exchanger.

Use connectors and water hoses to connect the heater and the
water pump to the water flow hose.

Lay a water hose from the discharge end of the water pump to the
water inlet socket of the heater and connect.
Heating characteristics
If the heater is switched on, the heat is initially fed via the heater's
own heat exchanger to the vehicle's engine only.
If the coolant liquid temperature has reached approx. 30 °C, the
vehicle fan starts and the heat is also routed to the passenger
compartment,
see Picture 10.
Picture 10
1 Heater
2 Water pump
3 Connector
4 Heat exchanger
5 Vehicle engine
3.10.2 Coolant liquid circuit “inline – engine preheating only”
 Disconnect the water return hose from the heat exchanger to the
vehicle engine.
 Use connectors and water hoses to connect the heater and the
water pump.
Heating characteristics
For engine pre-heating only, set the temperature controller to “cold”
and switch off the fan. There is thus no heat discharge into the
interior of the vehicle,
see Picture 11.
Picture 11
1 Heater
2 Water pump
3 Connector
4 Heat exchanger
5 Vehicle engine
3.10.3 Cooling liquid circuit with non-return valve and
thermostat

Cut the water flow hose from the vehicle engine to the vehicle's
heat exchanger and insert the non-return valve.

Cut the water return hose from the vehicle's heat exchanger to the
vehicle engine and insert the T-piece.

Use water hoses to connect the heater and water pump to the
thermostat, the non-return valve and T-piece – as shown in the
sketch.
Heating characteristics – small cooling water circuit
Up to a cooling water temperature of approx. 70°C, the heater's heat
is fed first to the vehicle's heat exchanger only – fast heating of the
inside of the vehicle,
see Picture 12.
Heating characteristics – large cooling water circuit
If the cooling water temperature continues to rise, the thermostat
slowly switches over to the large circuit (full switchover is reached
at approx. 75°C) – heating of the inside of the vehicle and additional
engine pre-heating,
see Picture 12.
Picture 12
1 Heater
2 Water pump
3 Thermostat
4 Non-return valve
5 T-piece
6 Heat exchanger
7 Vehicle engine
Note
The thermostat, non-return valve and T-piece must be ordered
separately, please refer to the “Product information” document for
the Order No.
Thermostat function
 Coolant liquid water temperature < 70°C – small cooling water
circuit:
– Socket 1 – open (to the heater)
– Socket 2 – open (to the T-piece)
– Socket 3 – closed (to the non-return valve)
 Coolant liquid water temperature > 75°C – large cooling water
circuit:
– Socket 1 – open (to the heater)
– Socket 2 – closed (to the T-piece)
– Socket 3 – open (to the non-return valve)
Note
Use the connections Item (1), (2) and (3) to integrate the thermostat
into the cooling liquid circuit,
see Picture 13.
25.2933.90.0001.0A EN | 06.2018 21
Technical Description | Hydronic S3 Economy