Ozone bubbles stop 2 minutes after powering in

[Jacanterbury]

my Hotspring Hottub has developed a fault. When I power it on it goes through its boot up cycle and after 10 seconds the ozone bubbles start and are very vigorous. They continue like this for 2 minutes and then suddenly stop . Everything else appears fine. If I power cycle exactly the same thing happens very repeatedly on timings.
All the jets work fine but the temperature slowly drops over time once the bubbles stop.

I’m wondering if the heating element is on a thermal cut out? Nothing trips out.

any advice would be much appreciated.

[CanadianSpaTech]

Sounds like a circ pump starting and stopping. 

[ratchett]

Yep, as CST mentioned - sounds like it could be a circulation pump issue.

The ozonator generates ozone via corona discharge - the ozone gas gets "sucked" into the water via a part called a "Mazzei injector" - this part sucks air/ozone into the water as it moves through the injector.  This part is actually responsible for creating the bubbles you see emanating from the vent, not the ozonator itself (this is important because many people make the false assumption that if they see bubbles, the ozonator is working, which is false - the ozonator could fail and the mazzei injector is still producing bubbles)

[Jacanterbury]

Thanks both.
Ok, though I’m puzzled as to why it appears to work fine for 2 minutes before stopping. This would seem to indicate that it’s not completely broken.

Any thoughts as to why it would decide to cut out in such a reproducible manner?

[In Hot Water]

Does your Hot Springs have a "Summer Mode "feature?