Bosch GWI-N Series Training And Service Information page 70

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