Quote Originally Posted by SmoothScales View Post
On the heat tape.
i'm assuming it's touching the heat tape, but is it under it? like sandwiched between the heat tape and rack (probably in a carved channel)? or resting on top of the heat tape between tubs?

the 97degree temp in tub indicates the t-stat probe is not reading your heat tape temp correctly therefore not turning off or holding stable at 89. this could be due to improper placement/contact or overexposure of the probe (to air). make sure the probe is directly in contact with the black heating element of the heat tape and cover the flip side/non-contact side with aluminum tape.