RAnco t-stat

[SamuraiZr0]

If the T-stat is wired with a reg extention cord(ungrounded) can that cause it togive incorrect temps?

[Spaniard]

Whether grounded or not it should not affect your temp readings.

[Somed00d]

not likely.. what is your problem? I have a ranco and it works great ungrounded

[shadi11]

i have my ranco set slightly higher than my desired temp. It is set at 94 degrees but it holds at 89. I have it set to a low differential. Do you have the probe set on your heat tape, And taped down so that its right against the heat source. That could be your cause for an inaccurate temp aswell. Could you describe your set up so we can figure out if its just placement or if you need to adjust for probe differential

[SamuraiZr0]

i have my ranco set slightly higher than my desired temp. It is set at 94 degrees but it holds at 89.

that's sorta my issue.. i have the dif set to 1 and it's in H1 mode. the issue is that it reads way off of my ambient. i have a dig themomometer (one of two that read identical to the ambient) they say my ambient is 79 my ranco sitting in the same room in the same spot reads 86. so i used my helix and the helix reads the ambient a 79 so the ranco has to be off.. but why?

[shadi11]

well. the ranco is designed for surface temp. i thought the helix did the same but i don't have a helix. so is your ranco sitting on the same surface as the helix. IF that is the cause you can still use the ranco just adjust the temp up. That is one of the reasons i am not going to buy another ranco the johnson controls has an adjustment for that purpose. Im hoping that i don't have this problem with my new herpstat.

[Spaniard]

that's sorta my issue.. i have the dif set to 1 and it's in H1 mode. the issue is that it reads way off of my ambient. i have a dig themomometer (one of two that read identical to the ambient) they say my ambient is 79 my ranco sitting in the same room in the same spot reads 86. so i used my helix and the helix reads the ambient a 79 so the ranco has to be off.. but why?

The probe or the actual unit could be not functioning properly. If this is a new thermostat I would contact the vendor and explain the situation; they should offer you a replacement.

[SamuraiZr0]

nah I bought it from someone on here... it's ok though I figured out it reads exactly 15 degrees over the surface temp so i'll set it 15degrees above where I actually want it. that seems to work out..

besides it's my back up used to control the heater in my snake room. and I gave test to the theory and it does work with the 15 degree difference.. so i guess i can live with it..