Viessmann VITOTRONIC 200 Installation And Service Instructions Manual page 66

Troubleshooting
Faults that are not displayed at the...
Heating circuit pump not running
■
Is plug 'live' between L and N?
sÖ
No
Check fuse F1, 6.3 A (slow). If the fuse has blown:
1. Pull plug .
sÖ
2. Replace the F1 fuse.
3. Repeat this test if fuse F1 remains intact but the pump
connection does not go 'live'. Possibly replace the main
PCB.
66
(cont.)
⇒
Yes
1. Check pump connection and pump.
2. Check any further switching devices that may be
installed (e.g. maximum temperature controller).