I have an inground Gerico Ocatavian spa. It came with the house so I suspect it to be from the mid '80's.
It is a 320 gallon spa with 4 jets and a skimmer.
I just replaced the heater with a new Hayward H100ID1.
Now, about 2 weeks later, only 1 of the 4 jets is really working. The other 3 have minimal pressure.
I cleaned the filter, checked and cleared all baskets and even shocked the water.
The motor/pump/impellar seem to be working fine.