Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 132

Indoor unit maintenance
Removing hydraulic components and EPP...
Removing the circulation pump head
1.
2.
Fig. 81
Torque settings
Torque settings for the circuit pump union nuts:
■
70 2 Nm
±
■ Torque for the screws on the pump head:
5 1 Nm
±
Status display, internal circulation pump
Fig. 82
132
(cont.)
LED Meaning
Flashes green. Normal operation, circulation pump
runs on demand.
Illuminates Circulation pump runs continuously
■
green. with maximum output, e.g. when
the PWM signal is interrupted.
No fault message
■
Illuminates red. Fault with fault message
■
Indoor unit is isolated from power
■
supply. LED lights up for the dura-
tion of the run-on time, approx 30 to
60 s long.