I've had a fl1 error flashing for a couple of months but with no other symptoms. I think it is a j350 or 345. Year 2007 or 2008.
Today I emptied and refilled the tub and found the heater will not kick in. The filters are almost new. (Although not Jacuzzi branded.) I did remove them and restart but no change.
All jets are working normally. I tried to feel the filter connection for suction as described elsewhere but couldn't feel much. That said, I'm in Scotland in January and with the water at 7.2 Celsius I didn't fancy fumbling in the water too long! ☺
Any advice would be greatly appreciated. Cheers.