Viessmann Vitopend 100-W Installation And Service Instructions For Contractors page 40

Troubleshooting
Fault indicators on the display
Displayed System characteris-
fault code tics
b0 Burner blocked
b8 Burner blocked
Repairs
Checking and cleaning the plate heat exchanger
Shut off and drain the boiler on the heat-
ing water and DHW sides.
40
(cont.)
Cause
Short circuit, flue
gas monitoring
sensor
Lead break, flue
gas monitoring
sensor
Note
Residual water may drain from the plate
heat exchanger during removal.
Measures
Check sensor (see
page 43).
Check sensor (see
page 43).