MR MESSKO MTRAB, Operating Instructions Manual, Page: 94 / 124

10 Maintenance, inspection and care
94 BA6820378-03 EN
10.3 Test button
If there was an error on the MTRAB, this must be acknowl-
edged prior to conducting a function test. If several errors were
present, these are to be acknowledged individually one after
the other. If an error remains present, it is not possible to con-
duct a function test at this time (see [
► Section 9, Page 83]).
It is also not possible to conduct a function test if the device is
heat-drying (yellow LED
is lit). If the test button is actuated
in this case, all LEDs flash simultaneously 10 times.
The test button can be used to force performance of a function test.
Quick test [ ► Section 10.3.1, Page 95]
If the test button is held down briefly (≤ 3 seconds), the humidity level in the
upper air spout will be displayed for 30 seconds.
Long test [ ► Section 10.3.2, Page 98]
If the test button is held down for a longer period (> 3 seconds) and then re-
leased, the following tests will be performed:
▪ Heating test
▪ Analog output test
▪ Failsafe relay test
▪ Ball valve test (MTRAB DB200G only)