Webasto Heater
Thermo Top C 300
Fan Blower
Indirect Plate
Heat exchanger
Header Tank
Radiator
(optional)
optional
Fresh
Water
Pump
Approx 7 lpm
= 5 lpm @ tap
Temperature
mixer valve
Webasto Heater
Thermo Top C 300
Fan Blower
Indirect Plate
Heat exchanger
Header Tank
Radiator
(optional)
optional
Fresh
Water
Pump
Approx 7 lpm
= 5 lpm @ tap
Fresh
Water
Pump
Approx 7 lpm
= 5 lpm @ tap
Temperature
mixer valve
TRV valve
Balance valve
Optional—valve &
link pipe used for
short circuit hot
water only in sum-
mer
The Webasto Diesel
Heating System
This installation uses an independent self contained coolant sys-
tem to provide heating and hot water.
This is achieved very quickly due to a small coolant circuit being
used which has a very quick warm up time, the hot water is pro-
duced via a plate heat exchanger therefore the hot water is ready
in around 5 minutes.
The Webasto heater is typically mounted externally on the vehicle,
whilst the header tank and plate heat exchanger utilise minimal
interior space. The blower units would be mounted in the area
where the heat is most required i.e. living area and the rear. These
2 speed blowers can operate independently or together & are
controlled by a thermostat. Heating & hot water on the move is
possible. The bypass (optional) is used for hot water only in order
to achieve a quick heat up time.
Operation–
Once activated, the Webasto Thermo Top C heater will use the vehicle’s own fuel in a combustion process
to heat the coolant via a heat exchanger. The heated coolant is then circulated round the heating circuit passing through
the fresh water plate heat exchanger & blower heaters by an integrated water pump. The Webasto unit is self regulating
& operates in a similar way to a domestic central heating system.
ECU
Water pump
Burner
Exhaust Silencer
Heat
Exchanger
Combustion Air Fan
Fuel Dosing Pump
Coolant In
Coolant In
Glowpin
Flame Detector
Glowpin
Flame Detector
Heated coolant Out
The indirect plate heat exchanger
is made up from a series of plates
which separate fresh water from
the coolant giving 2 independent
circuits. A transfer of heat takes
place when the fresh water circuit
is passed over the Webasto cool-
ant circuit plates. Maximum
heater energy is given to the
blowers until a demand for hot
water is received. A thermostatic
mixer valve is fitted to control the
hot water temperature to the taps.
Specification subject to change without prior notice
THE CONTROL PANEL -
is most
often located close to the door to the
living area of the vehicle. (Used for
activating the heater, a green light
illuminates during operation, and for
the selection of the fan heaters high
and low speed). Close by this panel
is the
ROOM THERMOSTAT
,
THERMOSTAT
—this is used to
regulate the ambient temperature in
the living area. This is adjusted to a
comfortable room temperature. Turn-
ing the dial clockwise requests a
higher temperature. When this point
is reached then the blower boxes will
switch off. The blowers will then turn
back on when the interior temperature
drops below the dial setting
THE THERMOSTATIC MIXER
VALVE
– This is used to determine
the hot water temperature supplied to
the taps (adjustable from 30 to 48°C,
anti-clockwise to increase the tem-
perature, clock-wise to decrease the
temperature).
Typically this is
around 42-45c. Adjust as required.
Anti clockwise = hotter (+)
On/off
Blower
Switch
Fresh Water
Visit www.butlertechnik.com for more technical information and downloads.
www.butlertechnik.com