What BRAND is this hot tub??? I used to have a Vita Spa, made down the road here, and the local dealer supplied some minor part no sweat, thing ran fine, bought used of course, added insulation around the tub and a new top that I had made by guys on the side work, costing about 150 bux TOTAL.....
wooden mind hopping in the thing right now, but installed an interior hot tub years ago.....
OH, edit.....I furgot to remember.....you can modify the typical capillary tube oven thermostat to a lower temp by an adjustment screw....the on/off is close enough for any hot tub, and did just fine as an engine fan controller years ago.....so adjust it down to a comfy temp....being a hot tub that should be about 105 or so.....
GOD I'm a cheap bastard......