Page 70 from 76 6 720 814 719
SM FP_Australia 2017/04 EN
E4
Air box NTC sensor detect high temperature inside room sealed box (T
box
> 80ºC)
Characteristic: NTC Temperature sensor
Lock Out Error
Burner shutdown but self reset by closing water
Problem solved?
End
Change wiring
Problem solved?
Replace control unit
See spare part list
No
No
Yes
Yes
Temperature inside
box reach high limit
(Tbox > 80ºC)
Check position of sensor (attached
at back cover of control unit)
NTC out of place and
touching hot surface ?
Measure the NTC electrical
resistance [R] (Ω)
[R] Ω = Current T air (ºC) ?
Correct position and fix
NTC in original position
Replace wiring
Check origin of high
temperature inside box
See spare part list
Yes
No
No
Yes
Refer to table with
values in Service
Manual