Thermo 90 S / Thermo 90 ST 5 Troubleshooting
503
Fig. 502 Fault indications on fault lock-out (page 2 of 2)
5.4 Visual check for assessing
the burner
The burner and the evaporator in the heater display
specific characteristics when they must be replaced or do
not have any fault source.
The criteria of a correct check are listed below.
5.4.1 Burner housing
• The start air hole (Fig. 503) must be clear otherwise
no start will occur.
Remedy
Carefully remove impurities from the start air hole
(e.g. using a 1.5 mm diameter wire). Remove the glow
plug first.
Fig. 503 Visual check, burner back wall
Fault indication Possible cause Remedy
9 Flashing pulses
(glow plug defective)
Cabling Check cabling for damage, discontinuity and
short-circuit
Flow plug defective Replace glow plug
10 Flashing pulses
(overheating)
Heater overheats Check coolant and top up if necessary.
After the unit has cooled down, press the
button of the temperature limiter before
switching on or fit a new temperature limiter
11 Flashing pulses
(circulating pump defective)
Cabling Check cabling for damage, discontinuity and
short-circuit
Circulating pump defective Replace circulating pump
1 Fuel pipe
2 Round seal
3Flame monitor
4 Insulation
5 Glow plug
6Housing
7Screw
8Bar
9 Start air hole
1
2
3
4
5
6
7
8
9
