I have a 2002 or 2003 Hot Springs Sovereign with IQ 2020 controller and a Watkins no fault heater (240V). About 2 weeks ago I noticed the "ready" light not on, it was set to 101 degrees. I turned it down until the ready light came on (at 97 degrees). Over a period of about 10 days the temperature the tub could maintain decreased until it could no longer maintain 80 (the minimum).

I ohmned the black and white heater wires and got 10.1 ohms (this should be good I think?).

I've verified the 20 and 30 amp connections are bringing 238V into the IQ 2020 controller.

The voltage from P3 to ground (one leg of the heater) is 118V, the voltage from P2 to ground is 0V (not good I think?). The circuit board under the K3 relay has a slightly burned spot.
I'm thinking the K3 relay may have burned the contacts which resulted in loosing the 118V on P2 thus causing the heater to not output. ?? I wish I had a schematic of the IQ 2020 controller to verify where the heater voltages come from. Ideas?
Thanks. -Mark

Sounds like you need to replace that left side 'heater relay board'.

Do you have 220 volts at the relay? If not replace it.

#73355, $105.00, bottom right of page, http://scarritt.com/tigerparts2.htm , comes with directions