Valeo THERMO DC 200, Installation And Operation Instructions Manual

Installation of the heater - fitting of important assemblies

Thermo DC 200

26

11.2. Connection to the vehicle's cooling system

The heating appliance is connected to the vehicle's cooling system 
according to figure 17. The volume of coolant fluid present in the circuit 
must be at least 35 liters. The water in the heating circuit of the heating 
appliance must contain at least 30 to 60% of a branded antifreeze agent. 
An up-to-date list of Spheros recommended anti-freeze agents can be 
found on the Spheros website.

Basically, the by Spheros approved water hoses must be used. If this is 
not the case, the hoses must at least comply with DIN 73411. The hoses 
are to be laid without kinks and also rising where possible for the proper 
bleeding of the heating appliance. The heater must be mounted below 
the minimum water level of the cooling circuit. Hose connections are to 
be secured with hose clamps against slipping off.
When installing the electric heater the direction of the flow of the cooling 
water in the circuit is to be considered (see figure 17).

ATTENTION:
The specified tightening torques of the hose clamps used must be 
adhered.

In the vehicle cooling system, or in the case of a separate heating circuit, 
only overpressure valves with an opening pressure of maximum 2 bar 
should be used.

Attention should be paid to the 

careful bleeding of the cooling system

without usage of  the circulating pump, before the first commissioning of 
the heating appliance, or after the coolant fluid has been replaced.
For that the additional venting option via the vent screw item 4, figure 17 
is to be used after the system has been filled and the pump has been 
switched on.
The heat exchanger and the water hoses of the Thermo DC should be 
pre-filled completely. Loosen the vent screw slightly until no air further 

emerges, but only water. Then retighten the screw (tightening torque - 
see figure 19).

ATTENTION:
If air bubbles are present, they could cause destruction of the car-
tridge heaters!

The heating appliance and pipes must be installed in such a way that 
they ensure a static bleeding of the system.

The correct degree of bleeding results in an almost silently operating 
circulation pump. An inadequate bleeding can lead during heating 
operation to the switching-off of the heating appliance due to overhea-
ting.

Where the U 4855 / Aquavent 6000C circulation pump is used, the circu-
lation pump is automatically switched off ca. 10 seconds after switching 
on, if the cooling agent is not present or there is blockage of the pump 
impeller, and it can be started up again after ca. 2 minutes. 
Where the U 4856 / Aquavent 6000SC circulation pump is used, the 
circulation pump is automatically switched off ca. 45 seconds after swit-
ching on, if the cooling agent is not present or there is blockage of the 
pump impeller, and it can be started up again after ca. 2 minutes.

ATTENTION:
Before commissioning the heating system, the water hoses, the 
circulation pump and the heating appliance must be filled comple-
tely.
Only by Spheros recommended anti-freeze agents may be used.