The Jetsetter is set up in 230V mode and is a 2002 model.

I'm resigned to calling in a spa repair technician, but thought i would post the details of my problem to see if I'm mission anything.

I noticed the ready light off a couple of days ago, and after checking the hi limit swtich, and circuit breakers to no avail, I opened up the IQ 2020 panel. The white wire feeding the No Fault 6000 heater is burned. The adjacent black wire leading to the main board also looks damaged. On the attached photo, the two wires are directly under the middle and right-hand relays. No other damage is obvious.

Wiring of the terminals looks correct per the Watkins manual.

Voltage reading across Terminals 1 - 4 are as follows (4 and 5 are jumpered per Watkins spec):

1-2 0
1-3 250
1-4 123
2-3 250
2-4 124
3-4 124

I just bought a house with the spa already installed, and am not looking forward to costly repairs though i'm sure the relay board at least is toast. Any advice is appreciated. thanks

Those burned wires are a very good place to start your troubleshooting. They burned because the spade connectors either came loose over time or corroded over time and generated heat. Replacement of the circuit board and the wire terminals (and/or) wires may be the only recourse.

Just need a new heater PCB- new ones with more sodder are available from the dealer- should still be under warranty if you bought it new.