172
F024 Temp. acc. bot-
tom open circuit
• Sensor is faulty
• Open circuit in sensor cable
• Sensor not connected
• Connect sensor
• Replace cable
• Check terminal (check plug
for secure fit)
• Exchange the faulty sensor
(plug on the I/O circuit board)
with a different sensor
• If a different fault appears, the
sensor should be replaced
• If the same fault appears, the
I/O circuit board should be
replaced
F025 Checking the
lambda
sensor
• Lambda sensor faulty
• Open circuit in the line
• Fuse F4 (on I/O circuit board)
is faulty
• Check lambda sensor, replace
if necessary
• Check line and plug
• Replace fuse
F026 The lambda
Sensor is faulty
• Lambda sensor is faulty or
heavily soiled
• Clean lambda sensor, then
recalibrate (parameter h-38)
• Replace sensor if necessary
F027 Check sum error,
parameters reset
to defaults
• Fault in the control EPROM,
all parameters will be reset to
factory defaults
• Check all settings and adjust
current values.
F028 Safety circuit
Emergency Stop
• Emergency Stop activated • Unlock emergency stop
• Acknowledge fault with main
switch off/on
F029 Safety circuit
Low on water
• Check water pressure • Unlock insufficient water
cutout
• Acknowledge fault with main
switch off/on
• Check plug on circuit board
22 /23
F032 Cleaning system
limit switch,
top
• Cleaning function blocked
• Faulty limit switch
• Check cleaning system
• Have limit switch checked by
a qualified electrician
F035 HC module 0
not connected
• Power supply has failed
• Bus cable is not connected
• Bus cable is fitted the wrong
way around
• Check the power supply
• Check connection of bus
cable
F036 Software not
compat. with
this hardware
• Software is not compatible
with this hardware
• Use a new software
• Notify HDG customer service
F040 Supply temp. HC1
open circuit
• Sensor not connected
• Sensor is faulty
• Have the fault fixed by a qua-
lified electrician
No. Fault Cause Remedy
Table 8/1 - Faults
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