Check Dhw Tank Temperature Sensor Or Low-Loss Header Temperature Sensor; Check And Replace Differential Air Pressure Sensor - Viessmann VITODENS 200 Start-Up And Service Instructions

Correction
(continued)
A
B
X7
1 2 3 4
A DHW tank temperature sensor
B Low-loss header temperature sensor
B
C
D
B
D

Check DHW tank temperature sensor or low-loss header temperature sensor

40
20
10
8
6
4
2
1
0.8
0.6
0.4
0.2
50 86
68
10 30
20
Tank temperature in ºF/ºC

Check and replace differential air pressure sensor

In case of fault messages regarding the differential air pressure sensor, check that
H the sensor was installed correctly.
H the electrical connections were made correctly.
H the O-rings in the adaptor are correctly positioned.
H the test nipples have been sealed with plugs.
If the error message persists, replace sensor.
C
To check O-rings:
D
1. Disconnect electrical plug-in
connection
2. Remove sensor B by pulling off in
an upward direction.
3. Check that the two O-rings C are
correctly located in the mountings
D of the adaptor.
A
4. Insert connection nipples of the
sensor in the adaptor of the gas
combination valve and snap into
place.
5. Reconnect the electrical plug-in
connection on the sensor.
122 158 194 230
104 140 176 212 248
50 70 110
40 60 80 100 120
A.
164
Troubleshooting
1. Disconnect connector "X7" from the
control unit.
2. Measure resistance of the tank
temperature sensor and compare
with the curve.
3. If the value measured differs
significantly, replace the sensor.
4. Repeat above steps 1 - 3 for
checking the low-loss header
temperature sensor.
Transducer power supply
X14.3 . . . . . . . . . . . . . . . . Red
X14.4 . . . . . . . . . . . . . . . . Yellow
X14.5 . . . . . . . . . . . . . . . . Black
Between red and black:
. . . . . . . . . . . . . . . . . . . . . . . 24VDC
Between black and yellow:
at standby . . . . . . . . 0.2 to 0.3VDC
at ignition . . . . . . . . . 0.7 to 1.0VDC
at low fire . . . . . . . . 0.5 to 0.6 VDC
at high fire . . . . . . . . 3.5VDC
41