electricity_bill
Registered

No Mark, it does it from the outset and carries on for some time.
I would ask:
Which model of Central Station?
What version of software in it?
Which model of Navigator?
What version of software in it?
Is the Navigator wired, or wireless?
For a start..
While it is not exactly the same as your problem, I have had a problem with my navigator which related to the batteries and connectivity. I have found that re-chargeables do not work very well (perhaps due to lower voltage? ). I tried putting a little foam block on the door to keep pressure on them but this did not really work. This issue manifests as the handset powering off randomly but usually when I put it down/move it or such. I do not have this problem when I use off the shelf batteries. crazy.......
I see no mention of which Wireless Receiver is in use?
Which ever receiver it is, it should be at least Firmware version 1.90, and once identified and if it's a 8133001 upgraded to Firmware version 2.10.
As for the other items, the Dimax 1200Z is running an out of date Firmware Version, which is at present V2.65.
400H Navigator, it should be running Firmware version V2.00d?
And is the following set?
View attachment 238423
It is possible that the mismatch of firmware versions across all of the above mentioned hardware could well be a factor in why the said equipment misbehaves.
A number of reported bugs were "fixed" with the later firmware upgrades, a full and informative list can be found using the Massoth Service Tool V3.2.0.0 by viewing the update history files under the Firmware Icon.
As ever a wealth of factual information can be found on the Massoth WiKi.
http://wiki.massoth.de/tiki-index.php?page=Zentrale+1200Z+8135001#Special_updates
Central Station 1200Z 8135001
Here you can find all needed firmware packages for your 1200Z Central Station.
DiMAX Update Tool, use strictly for Central Updates!!
Firmware German/English 2.65
1200Z-V265_DE.dimax
http://wiki.massoth.de/tiki-index.php?page=8134001+Navigator
8134001 Navigator en
Manual for Navigator
So the technical explanation of the problem is: "It was broken".... pretty funny