Servicing
5
Installation and maintenance instructions for wall-mounted condensing gas boiler 600 - 28C • 01/2004
53
Subject to modifications resulting from technical improvements!
Boulter Buderus Ltd. • http://www.boulter-boilers.com
z
Measure the resistance of the return sensor (see fig. 77).
z
Disconnect the plugs of the hot water out flow sensor
(fig. 78, item 1) and the hot water heat retaining sensor
(fig. 78, item 2).
z
Measure the resistance of both sensors (see fig. 79 and
fig. 80).
z
Use a second-reading thermometer to measure the
temperature around the sensor.
z
Compare readings with values shown in the table below. If
there is any mismatch (i.e.
≤
10%), the sensor is defective.
fig. 77 Measure resistance return sensor
fig. 78 Disconnect plugs of hot water sensors
1
2
fig. 79 Measure resistance of hot water out flow sensor
Resistance values of the sensors
Temperature
in °C
Resistance
in
Ω
Temperature
in °C
Resistance
in
Ω
0
29.490
5
23.462
55
3.271
10
18.787
60
2.760
15
15.136
65
2.339
20
12.268
70
1.990
25
10.000
75
1.700
30
8.197
80
1.458
35
6.754
85
1.255
40
5.594
90
1.084
45
4.656
95
940
50
3.893
100
817
Table 11 Resistance values of the sensors