Please help! My tub is about 8 years old. It has always worked great until recently. No heat! Topside is calling for heat also flashing the dreaded 3 dots. I have 240v to board but nothing at heater. I changed pressure switch and cleaned filters but nothing! The service tech wants 900.00 for new pack so i sent board to one of these board repair guys who charged 100.00 and replaced heater relays and says that everything works fine in his shop. Now i'm lost! Any ideas??

If you have power to the board but nothing to the heater elements then it's got to be either the board, a relay not making or the wiring got put back wrong or broken. There should be a high limit somewhere and it may be that if it's stuck open.

Do you have a schematic?

Could be a problem with your water temp sensor as well. In december I had my Gecko board repaired by the guy out in Arizona for around the same price. Mine Also flashed the 3 dots after I first filled the tub. I found that the water temp sensor had been pulled back from the sleeve in the shell, so I pushed it back into it's sleeve and gave it some time and the water started heating up pretty quickly after that.

Three flashing dots usually is a flow issue, but, the pressure switch stuck closed will cause this also, to test : unplug wires from the switch, power the tub up and then JOIN the wires with a jumper wire and then see if the heater is energized (by using a clamping amp reading meter) around 15-20 amps should be there if the heater is not open.