Is my ozone working?

[tony]

You could also put your hand on the ozonator and feel it running, main pumps should be off for this.

 Any chance you recently had a power outage??  That can allow water to siphon back up the 1/4" tube and get past the check valves, which does happen once and awhile.  

 I have seen some spas, that whoever installed the ozonator left the 1/4" tube on the floor inside the cabinet, instead of coiled up above the waterline, and it actually will siphon all the water out of the tub, through the ozonator.  

About the only way to tell if the actual ozonator is working is by feeling it as you mentioned or by listening for the slight hum the ozonator makes.  Even if the ozonator is not working, though, there should still be bubbles as the ozonator does not pump ozone but is drawn by the vacuum caused by the Mazzei injector.

It is amazing how many dealer installed ozone systems do not use a Hartford loop above the water line and only rely on the little check valves to stop water from backing up into the ozonator.  

[SpaNE]

With your particular spa and factory ozonator, it is most likely either a kink or blockage in the ozone tubing, the check valve or the Mazzei injector.  The check valve is most prone to failure.  It is very easy to check.  If you remove your front cabinet panels you should be able to locate the ozonator itself.  It should be a gray or blue box approx 8" x 5" with a 1/4" tube comming out of it along side a short 1/4" tube for air to enter.  Follow the long tube.  It should form a loop above the water line and end up at a special Tee at the water return line.  This tee is the Mazzei injector.  Somewhere along the 1/4" tubing there should be at least one check valve.  It is a small plastic device.  Sometimes the Mazzei injector can foul up and needs to be freed or cleaned up.  The only way you will know if your check valve is bad is to blow through it.  If you're nervous about the nitric acid, attach a clean short length of tubing and blow though that.  Your ozonator should blow bubbles whether the ozonator itself is working or not.  The bubbles are only an indication of the Mazzei injector and the tubing in good shape and enough water volume to allow the injector to work properly (thus the dirty filter issue).

Thanks for all the suggestions, especiall Tony and Jacuzzi Jim.  You guys are great.

If it ever stops snowing, raining and sleeting in Boston I will open the cover and take a look, however, I am inclined to simply call the dealer to check it out since it is under warranty.  I checked the filters yesterday and they are fine - I also just cleaned them less than 2 weeks ago when I did a water change.

One outcome from this experience is that I have proved to myself that ozone works to help keep the water clean.   My water starts to get cloudy now in 2 days or so if I don't add dichlor (on days I don't use the spa).  When the ozone was working I could easily go 4-5 days before the water would look a bit cloudy.

[drewstar]

The other thing to check for is to make sure you didn't "fat finger" in an energy saving mode.   These modes can affect filtration and I beliver the circ pump.