Hi Neil - when I first plugged the sensor in I used it with zero compensation and still had the spikes. I've now run it for over 24 hours plugged into the 2925 and it tracked the room temperature perfectly - no spikes at all. So it does appear to be an issue with my AP903s.

I have now plugged the sensor back into the AP903 in the garage. It's reporting a current temperature of 20.31C, which is fine. However, it is also reporting for the last 24 hours a maximum of 199C and a minimum of 13.12C - yet the sensor has been plugged into my 2925 for more than 24 hours!

OK back in the garage for 24 hours - only 1 spike to 199C at around 00:45. I guess that's an improvement.....

3 spikes to 199C between 0150 and 0650 last night, so maybe not an improvement after all...

Just a thought, are these spikes at regular and precise intervals? If so then it might be an internal process disturbing it which is why others are not seeing it. If so then it might be worth switching functions off until it stops occurring?

Neil..

Hi Neil,
When I first noticed them they appeared to be occurring at approximately 8 hour intervals. Last night they occurred at about 0150, 0400 and 0645. I'm not aware of any processes occurring at those times, although as in most houses these days I guess that there are lots of gizmos doing their own things - but as I say, when plugged into the 2925 it doesn't happen at all.

Piste Basher wrote:
... but as I say, when plugged into the 2925 it doesn't happen at all.

You could try the 2925, with the sensor, in the garage for completeness :wink: