Hello,

I have a Draeger Permox Silent Care with the following symptoms:-

- If switched on with airflow restricted (4Lpm for example), then it triggers an immediate alarm mode and shuts down the compressor.

- If switched on with airflow unrestricted (regulator fully opened) it runs just fine and produces oxygen.  If left to run, after 5 minutes you get a 3-beep alarm, but it continues to run.

- One it is running unrestricted,  if the airflow is restricted (to 4Lpm for example), then after a while it will go into a single continuous alarm and shut down the compressor.

- I have checked all the pipes, no kinks or snags found, and with the regulator fully open it easily exceeds the flow measurable by the flow meter.

- Filters are all clear.

- Compressor runs nicely

Can anybody please advise on what may be wrong?

I notice there is an RS232 port and also a header pin block on the PCB.  Can I use these to aid diagnostics?

Is there ANY technical or service documentation available apart from the standard use manual?

I am located in Hampshire U.K..  Are there any service places nearby?

Many thanks for any help or advice.