Help with Digital Temp Control

[Bar2ska]

Hi Guys,I need some input with a Ranco ETC 111000 Digital Temp Control I used in my home built smoker.Opinions on if I should install a different style T-stat? Here is my problem.Placement of the thermistor,So far wherever I put the thermistor it does not cool down fast enough to keep my door thermometer at a fairly steady temp.Door thermometer drops 15 degrees before thermistor cools enough to kick back in.I installed a baffle under the door thermometer and that helped a bunch,so the draft wasn't cooling it off.But the thermistor( which I did the same thing) ,so far I havent been able to find the magic location.Any thoughts?

[SixPack]

Bar2ska are you sure the door thermometer is reading correctly.
Does it read the same as the ranco when the set point has been reached?
If you feel sure your door thermometer is correct you could try setting the differential range on the ranco so it turns back on quicker.
I believe they have a 1 to 30 degree range. Maybe set it to only drop 5 degrees and then turn back on.
I don’t know a lot about this high tech stuff but maybe it’s a place to start.
Someone smarter than me should be along shortly to help.

[Bar2ska]

Hi SixPack,I guess I never thought about the door thermometer being off.will test this.The temp does get pretty close to reading the same though.Within a few degrees.I have set the temp drop on the temp control which does not help the situation.The problem is the thermistor is not losing it's heat fast enough to kick the unit back on in time.Maybe the difference in heating a metal thermostat on the door and a plastic thermistor on the temp controller.I am going to move the thermistor down lower again.Basically trying to trick it in a way to jive with the door therm. But I had better make sure the door therm is correct.Thanks,Mike B.
Oh yea,they say not to mount around radiant heat so it may be hard to do.

[Richtee]

"float" the thermistor as much as you can..IE: keep it separated from any grill or large thermal absorbing/holding mass mounting maybe.

Picts of the setup might help.

[MossyMO]

As Rich suggested, I mounted ours to a wooden dowl midway, central in our smoker... I didn't want the thermistor hanging to get snagged during use and figured wood dissipates heat quicker than metal.


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Here it shows location between grates.

[Bar2ska]

Hey Guys,I think I finally figured it out.I bet I have15 hours into this temp problem.What I ended up doing was using two 4 inch electrical boxes.I knocked out one of the holes in the side of the boxe slid it over the door thermostat so the box is blocking the draft from under the thermostat.Holds a steadier temp.The thermistor I ended up mounting about 8 inches off the bottom of the smoker on the right hand side,I mounted a 4 inch box over the top of the thermistor so the heat draft could not hit it directly.Also after seeing Richtee's and Mossy Mo's posts It kind of hit me (after a couple hours).I had the thermistor zip tied to a dowel.With a thermistor it has to sense strictly air temp.Being attached to the dowel it was keeping it warm not allowing it to drop.Now with the changes,when I set it to say 140 it hits 140 on the door and temp control(shuts off),door rises to 145 ,temp control to 143.Within say 5 minutes they both drop about evenly,the temp control drops to 139 and kicks back in.I think it's about as close as I can get it.Thanks guys.Amazing what some outside input does for a guy,gets you thinking in a different direction.

[Bar2ska]

Oh, also what is the best way to calibrate the door thermometers? If there are other places on the forums where questions like this are posted would you let me no so I don't bug the the hell out you guys asking the same questions that have probably been asked before.So much info on here will take forever to get to it all.

[MossyMO]

Check the thermometer by placing it in water as it just reaches a boil, should read 212º.

[Bar2ska]

Thank You