Viessmann VITODENS 242-F Installation And Service Instructions Manual page 146

Troubleshooting
Repair
(cont.)
2. If necessary, correct the position of
the flue gas temperature sensor or
replace faulty flue gas temperature
sensor.
Checking the temperature limiter
If the burner control unit cannot be reset
after a fault shutdown although the boiler
water temperature is below approx.
75 °C, check the following:
A
146
3. Press reset button R and repeat com-
missioning.
The check is repeated until it is com-
pleted successfully.
1. Pull the leads from temperature lim-
iter A.
2. Check the continuity of the tempera-
ture limiter with a multimeter.
3. Remove the faulty temperature lim-
iter.
4. Coat the replacement temperature
limiter with heat conducting paste
and install it.
5. After commissioning, press reset but-
ton R on the control unit.