During all active operating phases of the heater, all electric components, the operating
voltage and functional irregularities are monitored and recorded.
In the event of faults always first check the following:
Is the fuel supply ok?
Is a sufficient amount of fuel in the tank?
Are the fuses ok?
Are the electrical connections and cables in order?
Are the combustion- and exhaust air ways free of obstructions?
A malfunction causes the heater to terminate its operation by a fault shut-off and to go into
the fault lock-out mode to prevent the heater from an automatic combustion restart. At the
same time the operation indicator begins to flash with a specific code (see below).
The fault lock-out occurs:
low voltage during a defined period
if combustion was not established during start-up
if the flame extinguishes during operation
extrinsic light
if the control device itself has failed or peripheral components are defective
Variants to reset the heater after a fault lock-out:
1. Switch off the heater and then turn it on again
2. Reset the control device, e.g. through disconnecting it from the power supply
3. „Off“ and „On” switching“ via the S-Bus diagnostic interface
4. Erase the data in the fault memory by means of the diagnostic tool.
Additional to the fault lock-out a heater lock-out occurs if safety related components are
affected. The fault code 12 will be displayed (see para. “Flash code“).
If a heater lock-out has occurred, the heater must be maintained and released by Valeo
trained personnel.
Malfunction
Flash code
The kind of malfunction is indicated from the operating indication light through a flash code
or if the pre-selection timer is used in the display (operation display). The flash code is
immediately generated after detection of the malfunction and will be kept until the heater
is freed.
The flash code comprises of a burst (sequence) of 5 short flashes depicting the break and a
defined number of long pulses corresponding to the malfunction number, which are to be
counted. After that the cycle starts with 5 short flashes again and so on.
The meaning of the number of long pulses is shown in the table below.
Table: Flash codes
No. of
Long
Description of malfunction
pulses
0
not used
1
No start within the safety time
2
Flame interruption, restart failed
3
Low voltage / overvoltage
4
Extrinsic light before starting or within the purge cycle
5
not used
6
Temperature sensor / overheat protection defective
7
Solenoid valve defective
8
Combustion air fan motor / control device defective
9
Circulating pump defective
10
Overheat protection has been activated
11
Electronic ignition unit defective
12
Heater fault lock-out - deactivation necessary
13
not used
14
not used
15
Revolution signal faulty
Operating and
service instructions
Thermo Plus
230/300/350
