Product Manual
4.2 Functional description
4.2.1 Switching on
When the heater is switched on, the
symbol appears in the control
unit or the operating display lights up.
4.2.2 Heating mode
– The water pump starts up and, following a preset sequence, the
combustion air fan, glow plug and metering pump are started.
– The glow plug is switched off once a stable flame has formed in
the combustion chamber.
– Depending on the heat requirement, the heater adjusts
continuously between the heating outputs: MAX – MIN– OFF
(pause mode). The temperature thresholds for these are
permanently programmed in the electronic control box.
If the coolant liquid is cold the heater starts in “Max” control stage. If
the water temperature rises to 75°C (water outlet temperature of the
heater), the heater adjusts the heat output continuously depending
on the heat removed (heat requirement), in order to keep the water
outlet temperature at a constant 75°C. The heater provides the exact
heat output required, if this is between the “MAX” and “MIN” control
stages.
If the heat output of the heater in control stage “MIN” is higher
than the removed heat (heat requirement) and the water
temperature rises to 85°C, the heater adjusts to control stage
“OFF” (pause mode) and then starts the after-run.
If the water temperature cools to 70°C during pause mode, a
controlled start follows in “MIN” control stage. The heater now
adjusts the heat output continuously, depending on the removed
heat, between the “MAX” and “MIN” control stages.
During pause mode the water pump continues to run and the On
symbol
continues to be displayed in the control unit.
4.2.3 Residual heat mode
In this mode the heating system uses the residual heat in the cooling
water circuit of the hot engine and distributes the heated air in the
vehicle interior. In this mode only the water pump and blower are in
operation.
Note
The residual heat mode function is possible in conjunction with the
Easy Start Pro control unit.
4.2.4 Pre-heater mode following lengthy stoppage
Following a lengthy stoppage (e.g. summer break) it is recommended
that you switch on the heater once while the vehicle engine is
running and cold. The empty fuel lines are filled quickly; the next
start of the heater (pre-heater mode) can take place without
problems.
4.2.5 Heating at high altitudes
When using the heater at high altitudes, please note:
Heating at altitudes up to 1500 m:
– Unlimited heating possible.
Heating at altitudes over 1500 m – 3000 m:
– The heater can be run for short periods (e.g. driving through a
mountain pass or taking a break in your journey).
– In case of a lengthy stay, e.g. winter camping, fault-free heating
mode cannot be guaranteed.
Note
If the Easy Start Pro control unit is used, the altitude must be
adjusted manually for the activated heater. See Easy Start Pro
operating instructions.
4.3 Control and safety devices
If the petrol heater does not ignite within 105seconds of switching
on (diesel heater: 70seconds), the start is repeated. If the heater
does not ignite within the specified safety time (240 seconds), a
safety shut-down occurs. After an unacceptable number of failed
start attempts, the control box is locked*).
If the flame goes off by itself during operation, the heater is
restarted. If the heater does not ignite or ignites but goes out
again within 10 minutes, a safety shutdown occurs. The safety
shut-down can be cancelled by briefly switching off and on again
(heater ON / OFF).
In the event of overheating (e.g. lack of water, poorly ventilated
coolant liquid circuit) the overheating sensor triggers. The fuel
supply is interrupted and a safety shut-down occurs. Once the
cause of the overheating has been eliminated, the heater can
be restarted by switching it off and on again (heater ON / OFF).
Requirement: The heater is sufficiently cooled (water temperature
<70°C). After a maximum of 10 shutdowns on overheating, the
control box is locked*.
If the lower or upper voltage limit is reached, the heater is shut
down automatically.
The heater does not start up if the glow plug is defective or if the
electric cable to the metering pump is interrupted.
The speed of the fan motor is monitored continuously. If the fan
motor does not start up, if it is blocked or if the speed falls below
40% of the set speed, a safety shutdown occurs after 60 sec.
Note
Do not repeat the switching off / on routine more than twice.
*) * Cancellation of the lock or reading out of the fault memory is
possible:
– with the Easy Start Pro control unit.
– with the EasyScan diagnostics tool.
– with the EasyStart Web operating software
30 25.2933.90.0001.0A EN | 06.2018
Technical Description | Hydronic S3 Economy