Viessmann FB2A Installation And Service Instructions For Contractors page 84

Diagnosis and service scans
Checking outputs (relay test)
Display
Output internal ON
Heating circ pump A1
ON
Cyl. prim. pump ON
DHW circ pump ON
Central fault ON
Solar circuit pump ON
Solar circ pmp min ON
Solar circ pmp max ON
84
(cont.)
Explanation
Output sK Internal extension
Connection to external extension H1
Connection to external extension H1
Connection to external extension H1
Connection to external extension H1
Solar circuit pump output on solar control module active
Solar circuit pump output on solar control module switched
to minimum speed
Output solar circuit pump on solar control module switched
to maximum speed