Thermoplan Tx0115 runout error

Hello
,Our Thermoplan Black and White One (taken over used) has displayed error Tx0115 (runout error) during cleaning after the milk cleaning tablet was inserted. However, the previous cold rinse had worked. Does anyone have any ideas for a solution?
Thanks in advance!

Hello, Probably the strainer in the milk cleaning key is clogged or the outlet on the milk pump. Here you can not really do anything yourself, best to call the technician or just disassemble the machine yourself.

Error no.: TX0115
Cause: Flow error
Fix: Too low water flow
1. Open mains water connection
2. Empty grounds drawer
3. Perform rinse
4. Check flowmeter
5. Check pump

Thermoplan Black&Whute3 CT Troubleshooting Manual page 27