I have an older Catalina Hawaiian 1997 with a Acura Power Station pack and a Gordon Digital Topside 4 button controls. My problems are that when the primary pump is running on low or circulation mode the heater is not on nor are the topside control lights (temp,heat,etc) but if i turn the jets on all the lights come on. Is it the control? I replaced the pressure switch and checked for flow obstruction, no change. Any ideas? Thank you.

I attached some photos of the spa equipment.

Occasionally, there's a toggle switch in the control box for (2) types of topsides. Try looking for it.

Did this problem present itself when anything else was done, or did it just happen one day out of the blue?

It happened when I refilled it after shutting it down for the winter. The only thing I did was drain all the water and disconnect the wet end from the pump housing. Thanks for the response.