Benchmark ZWB 7-29 CC1 Installation And Servicing page 74

Failure identification procedure
CC
flashing.
Outside temperature NTC sensor not detected.
(Boiler heating as if outside temperature is -20˚C)
Check
1. Outside temperature sensor AF2
connected to Terminals A and F on
TA 211 E?
B Power OFF the appliance.
2.
B Disconnect outside temperature
sensor and test resistance
R = ∞ or R = 0?
26
Action
↓2.
yes:
B Power OFF the appliance.
no:
B Connect outside temperature sensor to Termi-
nals A and F on TA 211 E.
B Turn ON the appliance.
CC? ↓2.
B Change the external sensor.
B Turn ON the appliance.
7 181 465 346 GB (03.02)