how is this possible???

[2kdime]

I've got my johnsons temp probe taped to the bottom of the tub. Set at oh say 92 for example. The acurite thermometer will read anywhere from 90 to 94! Now I know there's a swing like that with on off thermostats.

My 2 helix's are the bomb. But yes I am still using the johnson on one of the sides of one of my tubs. My question is.

How can the temps inside the tub read higher than what the thermostat is set at? I'm always having to fiddle with it. Currently set at 92. And is reading 94 inside the tub???? What gives???

2 more helix's will soon be on the way.

[Spaniard]

Johnson's are on/off thermostats so you get a couple degrees of swing; unlike your helix which is proportional and is always on adjusting power levels to maintain the pobe temperature.

[2kdime]

I knew that. But my question is why is it swinging as much as 2 degrees ABOVE my set temp?

I can see a temp swing down. Like set at 92 and gettin temps like 90 to 92. But I'm getting temps PAST my set temp. I just didn't think that was right.

As of right now I have to keep watching it. I can't leave it at 92. I get temps from 90 to 94. Set at 94 ill get temps from 92 to 96.

[sweety314]

What is the differential set at????? If it's more than 1, then you'll get the broader range of temp swings. All the t-stats I own are JCs, and I've set the differential to 1. Now, that means it will click on and off more frequently in a room that has large temp jumps (like my old house's bedrooms & livingroom where the snakes were) but now that they're in a room w/a steady temp, they don't on/off as often.


Check and maybe reset the differential and see if that will help.


RuLyn

[2kdime]

Differential is set at 1. Everything on the thermostat is set how it should be.

My tubs are also in a room with pretty steady temps. Anywhere from 76 to 80 degrees.

I hate worrying about stuff like this. I just want everything perfect. Would it be better to tape the probe to the flexwatt underneath the tub? Or leave it on the bottom of the tub right above the flexwatt.

I figured I'd get more stable temps that way. My helix's are set up that way and they're fabulous.

[AzureN1ght]

I think RuLyn's got it right. From what I understand about on/off thermostats (I use proportional), your thermostat will crank power to the heat source 100% until it hits a certain temperature (this is where the differential setting is important), then it shuts off. If your differential is set to 1--I think that means your T-stat can get up to 1 degree above your desired temp and 1 degree below before it shuts on or off. If it's set to 2, two degrees above or below your desired temp, etc.

Hope that's what the issue is!

[Kagez28]

well when you are running the flexwatt (or whatever UTH you have) at full power till it hits 92˚ it's not gonna shut off and magically stay at 92˚. it's still gonna be giving off heat which will raise the temp until it cools off enough.

and just a side note... did you say you have your probe taped IN the tub? putting tape inside the enclosure is pretty risky. and so is having the probe in the tub. ideally you should put the probe between the UTH and the bottom of the tub. there you and use all the tape you want and your snake is not at risk or getting some tape on him, or moving the probe off the UTH. both of which can cause some bad things.

[2kdime]

True thatd make sense. But differential is set at 1. And it can't be taken down any lower.

Its only started doing it lately. Which is why I started this thread. I used to have it set at 94. And get readings from 92 to 93 or so. Maybe that's just on off thermostats for ya.

[2kdime]

Yeah kevin don't worry

Its set up correctly. The only probe inside the tub is the thermometer. On the bottom of the tub underneath the newspaper.
All my thermostat probes are taped to the bottom/underneath the tub.

I was just wondering if I'd get more stable temps if the thermostat probe was taped to the actual flexwatt. And not the tub bottom.

[sweety314]

I think RuLyn's got it right. From what I understand about on/off thermostats (I use proportional), your thermostat will crank power to the heat source 100% until it hits a certain temperature (this is where the differential setting is important), then it shuts off. If your differential is set to 1--I think that means your T-stat can get up to 1 degree above your desired temp and 1 degree below before it shuts on or off. If it's set to 2, two degrees above or below your desired temp, etc.

Hope that's what the issue is!

EXACTLY!!! That's how they work...so the higher the diff. setting, the greater the range in temps before it either turns on, or off.