Operating instructions

% Plug for the cylinder primary tem-
perature sensor
1.
&
Boiler water temperature sen-
sor
Pull the leads off the boiler tem-
perature sensor and check the
resistance.
&
Cylinder primary temperature
sensor
Pull the plug % from the cable
harness on the control unit and
measure the resistan ce.
&
Flow temperature sensor
Pull plug " X3" off the control u nit
andmeasuretheresistance
across terminals "X3.4" and
"X3.5".
2. Check the sensor resistance and
compare the actual values with the
curve.
3. Repl ace the sensor in ca ses of
severe deviation.
Danger
The boiler water te mpera-
ture sensor is im mersed in
the heating water (risk of
scalding) .
Drain the boiler before
replacing th e sensor.
Repairs (cont.)
81
Troubleshooting
5692 619 GB