Check temperature switch
Condens 7000 F – 6720871560 (2019/11)
54
15
Check temperature switch
If service code 6A 578 is continuously displayed (
temperature switch on the burner must be checked as follows:
Fig. 63 Display of service code 6A 578 (example of display using
MX25)
▶ Pull plug off temperature switch.
▶ Measure electrical resistance across the contacts of the temperature
switch (
Fig. 64).
If the value measured is < 1 Ohm (or signal tone, depending on
measuring device), the temperature switch is ok.
If no value, or a resistance of > 1 Ohm, is displayed (
Fig. 65)
contact the plant customer service to arrange a return and replace
the burner.
Fig. 64 Measure the electrical resistance across the contacts of the
temperature switch (temperature switch ok)
Fig. 65 Measure the electrical resistance across the contacts of the
temperature switch (temperature switch not ok)
16
Testing the differential pressure switch
If the service code 8L 534 is continuously displayed, the differential
pressure switch (
Fig. 34, page 32) must be tested as follows to make
sure it is working correctly:
16.1
Test the continuity of the differential pressure switch
at negative pressure.
The differential pressure switch is closed during operation. The contacts
are closed.
The fan must be switched on in order to simulate an operating condition
with negative pressure.
▶ Put the control unit on standby (
Technical documentation of
control unit).
▶ Pull off plug (PWM signal) [1] at fan. The fan runs.
Fig. 66 Pull off plug (PWM signal) at fan (boiler rating 200-300 kW)
[1]
PWM signal plug, boiler rating 200-300 kW
Fig. 67 Pull off plug (PWM signal) at fan (boiler rating 75-100 kW)
[1]
PWM signal plug, boiler rating 75-100 kW
00100012723-001
0010014359-001
OFF 1000
200
200m
200m
20m
20m
10A
2
2
20
20K 1K
200
2m
200
1000
200
200m
200m
20m
10A
2
2
20
200K
2M
2m
200
AC
V
DCV
DCA
AC
A
> 1
0010014360-001
OFF 1000
200
200m
200m
20m
20m
10A
2
2
20
20K 1K
200
2m
200
1000
200
200m
200m
20m
10A
2
2
20
200K
2M
2m
200
AC
V
DCV
DCA
AC
A
0L
0010014348-001
1
0010015321-001
1