I refilled my Jacuzzi Caressa as I have in the past, I started the jets, they work fine, the next push on the airswitch should give me heat and low pump speed. The heat comes on for about 2 seconds and kicks off, I believe this is due to no flow, the pump does not seem to go to the lower speed. I am on 110V. The tub serial #878000. The control module doesn't appear to have a name on it other then Jacuzzi. This is an older unit, there are no electronics in the control module. I am not popping any breakers or GFI, any time I go back to the jets they work good. Any help you can give me will be appreciated.

what is kicking off...high limit?

When I push the airswitch to heater mode, there is a little lite that indicates the heater came on, it stays on for about 2 seconds and goes off, there is an audible click from the control module, if I watch the inside of the module it is a mechanical relay that connects to the heater that drops out. If you have a diagram it is RY3. During the 1 or 2 seconds that the heater indicator lamp is on, there is no flow from the pump. I have requested a service man, I explained my tubs symptoms to him and he felt it needed to be bled, I think my jets are working fine, pushing a lot of water, why would I have to bleed out air ? This guy is showing up next Thursday, I'm afraid he is not my best option, if I can get it running I can cancel the service call.

If your heater assembly is fed by 3/4 or 1" hose, you will want to investigate the circulation pump and/or flow switch. The heater is likely shutting off due to lack of water flow.