Valve actuator air going to sleep

[Harry Phelps]

It appears that one of the above I am using went to sleep last night and didn't wake up when required to do so, anyone else had this problem?

It should have opened allowing a rad to heat up this morning but didn't, I used Device Status to have a look at it and right clicked on it to wake it. I had to do this a couple of times though, is this normal?