ok i have three tubs all using the exact same heat pad until i get my flexwatt and they are all plugged into the same herpstat. the temps were the same when i first plugged them in, but now they are all over the place. one keeps hitting 97, one stays at 89, and one goes from 89-95. my herpstat is set at 92 but the acurites are all saying different temps. they have new batteries and the probes are all on the same spot over the heat pad. any suggestions??