Ranco controller probe off?

[mloebl]

I had three older heaters in my fuge ranging from 175w to I think 200w all set for about 79F. My temperature sat pretty rock solid at those temps with only slight fluctuations of +/- .7F during the day with lights on or off. I set up insulation on the sump and fuge as I noticed the heaters were on most of the time, and figured as they were old (and cheap) that I didn't want to rely on them anymore. Just got a brand new Ranco single stage with two 500w titanium heaters and took out all the old heaters. The probe is in the fuge, and the heaters are in the sump now rather than the fuge due to their size. I notice that while the Ranco probe reads 80F (the set point), the other temperature sensor which is on the same clip, is reading 78.xF. I noticed the Ranco didn't kick in until the temp was down to about 78.2F or so and it reported 79F on the front (I have a 1F delta set up.) Is this normal for it to be off by ~2F? Can I recalibrate it?

Thanks,

-Mike

 

[rjdudek]

2 degrees off seems a bit much for a temperature sensor. That technology is pretty accurate these days. My ACIII is within 0.3 of a traceable Fluke probe.