505
Thermo 230 / 231 / 300 / 301 / 350
5 Troubleshooting
5.3.2.2 Fault Symptom "Flame-out"
NOTE:
Heaters with control unit 1572D:
If the heater performs 5 subsequent attempts to start due
to a malfunction, the heater enters an error lockout and
stops any further attempts to start. This error lockout is
superior to the normal error lockout condition.
The error lockout reset is achieved by switching the heater
on and disconnection of the heater power supply during
run-down.
5.3.2.3 Fault Symptom "Low Voltage"
NO
YES
Switch on the heater.
Is the combustion air fan
operating?
Are the power supply,
fuses, plug contacts,
relays o.k.?
(control unit 1572 only)
Replace defective
electrical components.
Is the fuel free of
bubbles in supply and
return?
Is the solenoid valve
o.k.?
(5.3.2.7)
Is the sight glass of the
flame sensor contami-
nated?
Is the nozzle free of
foreign matter and
deposits?
Is the fuel filter contaminated
or jellied?
Replace solenoid valve
Clean disc and sight
glass.
Replace nozzle.
Replace filter or check the low
temperature rating of the fuel.
Is the fan wheel free to
move?
Control unit defective,
replace.
Is the motor o.k.?
Check the hood, motor
and fan wheel.
Replace the motor.
Is voltage present on plug contact A3?
Is electrical wiring
o.k.?
Make electrical
connections.
Replace power supply
line.
YES
NO
Disconnect heater from battery supply.
Is battery properly charged?
Connect heater.
Is voltage between plug contacts A3 and A6
approx. 0.5 volts less than on battery?
Control unit defective, replace.
Is electrical power supply line
to heater o.k.?
Control unit defective,
replace.
Summary of Contents for spheros thermo 230
Page 70: ...memos...
