Ugh, someone help me with my Ranco...

[SlitherinSisters]

OK...maybe I got confused about the OP question. The Tstat will always have to be higher than the temps in the tub if you have the probe on the heat sourse. That will be the case with whatever brand Tstat you use. I thought she meant she sets the ranco on 98 and the actual reading on the ranco was 93. Maybe the OP will clarrify exactly what she meant. If you have the differential set at 5 and the probe on the heat sourse you will have to set the Tstat 10-20 degrees higher than the temps in the tub.

No, I totally understand that, but even when I have the probe directly on the flexwatt, it still doesn't get all the way up to the temp I set it at. For example, when I put the probe directly on the flexwatt, with the Ranco set at 88, it only got up to 86 according to the Ranco, so it never shut off, it just kept running it at 86 like it's a proportional stat.

Now I have the probe in the tank, because that's the temp I want the Ranco to adjust for. I'm waiting for it to slowly heat up the tank as we speak and see how far it's off in temp.

Long story short, I think I'm sticking with Helixes from now on, lol. What a headache...