My solenoid has turned off 2 hours ago.
I'll check it tomorrow if it's hotter than before.
You can open it very easily. I think you probably
already know how to open it but I'd say it away.
Just unscrews those 4 screws and you are done.
I opened it once when my bubble counter was still
bubbling after shutting it off, and solved it.
I have problem about stability of bubble rate only
for the first few days after changing to a new cylinder.
After that it's very stable, the tolerance has been around
0.5-1 bubble per minute. My working pressure had been
around 25PSI. The stock needle valve is hard to adjust though,
too coarse.
Azoo's manual says the factory setting is 4-6 KG/CM2.
But I've found that it is just the pressure when we attach the
regulator to a cylinder for the first time, then open the cylinder's
valve when the solenoid is closed. It will gradually turn down
to real working pressure shortly after use (probably 30 mins).
A few days ago, I've changed the working pressure to 21-22PSI.
The reason is nothing special. It's just because I was trying
connecting something inbetween the regulator and the solenoid,
and tried to find a suitable working pressure. The ‘experiment’ failed.
And I just leave it at that (21-22PSI). Still works fine.
BTW, the stock solenoid uses 1/8" NPT thread.
Cheers