High Limit Safety Cut-Out - Viessmann VITOLIGNO 300-H Series Operating Instructions Manual

Start-up/shutdown
Steps to take in the event of overheating

High limit safety cut-out

Triggering the function
If the boiler water temperature exceeds 95 °C, the
thermally activated safety valve triggers heat transfer
via the safety heat exchanger.
If the boiler water temperature exceeds 100 °C the
high limit safety cut-out responds.
Note
The high limit safety cut-out can only be reset man-
ually.
Cancelling the function
The high limit safety cut-out can only be reset
(unlocked) once the boiler water temperature has
reached approx. 70 °C.
After each triggering of the high limit safety cut-out,
check that the thermally activated safety valve is reset.
!
Please note
If the high limit safety cut-out is not reset, it
inhibits the safety equipment function and can
damage the boiler.
Always carry out the following steps.
Vitoligno 300-H, 50 to 60 kW
B A
Fig. 9
1. Slide cover on the programming unit to the
A
right.
2. Press green button
out.
A faint "click" will be audible; the high limit safety
cut-out is reset.
16
on the high limit safety cut-
B
(cont.)
3. Close cover
A
4. Acknowledge the excess temperature on the pro-
gramming unit of the control unit with
Vitoligno 300-H, 80 to 150 kW
A
Fig. 10
1. Open the front door.
2. Press green button
out.
A faint "click" will be audible; the high limit safety
cut-out is reset.
3. Close the front door.
4. Acknowledge the excess temperature on the pro-
gramming unit of the control unit with
on the programming unit.
d
on the high limit safety cut-
A
d
.
.