Spillover on while hot tub is heating

Hi,
I have just encountered a problem with the spillover on my hot tub. When I activate the hot tub (heating etc) the spillover stays on (obviously it should not and has not in the past 6 years) moving the heated water into the pool.

A quick fix I guess is hitting the dip switch to off for the spillover but that is only a short term solution. I think the problem must be in the remote panel and maybe I should reset it but I would like to avoid reprograming if I can.

Does anyone have any other solutions or thoughts? Jandy Aqualink RS 8