Type 1 son will not wake up

Thanks for the comments above. Firstly this pump has to be calibrated regularly. The blood readings are never the same as a true blood test since the CGM canular takes a reading from in the fatty part of the abdomen which is why true blood tests still need to be taken. We will review the basal rate settings but as I say he is a teenager aged 17 with emotions running high and affected by all manner of school tests, sport, anger, anxiety etc. all of which make forecasting sugars at night almost impossible. If he could only wake up at night when his alarm went off we would all be more reassured which is why we chose the new Medtronic one in the first place but at least it cuts off the insulin when he goes below the threshold set. Yet it just doesnt guarantee that his sugar wont drop into hypo.

One issue with the Medtronic 640 pump is that if you put on a temporary basal rate eg. 80% after Sport the alarm will not trigger if he goes high or low. Cannot understand that ! So we tend not to use temporary basal rates so we can hear the alarm and stop him in a hypo. Several years on we are still putting on the baby listener at night and adjusting high and low readings. He is being a typical teenager and not testing all day. Last night he went to bed at 30. But we cannot be on his case all day and are trying to make him independent. Last night I had to get up 3 times just to get his blood down to a reasonable level and calabrate the sensor when it was under 22 as you cannot calibrate above this level.
To the person who said he needs a sleep - my son sleeps well, too well. That is why he doesnt wake up when the alarm, buzzer, etc. goes off. He cannot be awoken at night.
I must say we are hoping for a new pump shortly as the Medtronic support has been awful. Very keen to sell, but sales staff lacking the knowledge and willingness to help with our problems.