repeated UTH failure on tubs. What am I...

...doing wrong?

I switched over to tubs about 6 weeks ago. Since then, I have had 4 UTH's fail. When I had glass tanks, I never had this problem - my UTHs lasted for years. I don't know what's going wrong.

Each 52qt sterilite tub has a medium UTH on the bottom. I'm using bark as substrate. Each has a good-sized, heavy ceramic water bowl in it, which is perfect for maintaining the humidity. The UTHs are connected to the thermostat, which is set for 85; I have a back-up rheostat attached as well. I initially tried small UTHs, but those did not get the temp up and stay consistent.

Now, the only thing that seems to be different with this set-up opposed to the glass tanks, is that now my snakes are dumping their water bowls. They are the same bowls they've had for years, and they never dumped the bowls in the glass tanks. I mean that literally; I will find the bowls completely dumped over and water soaking everything and driving the humidity up considerably.

My husband thinks that when they dump the bowls, the water pools on the bottom of the tub, it heats up and burns through the tub, which then shorts out the UTH. Admittedly, there are a couple of small holes in the bottom of each tub and subsequent scorch marks on the UTHs.

So, what am I doing wrong? It is getting expensive to replace all of these UTHs.

I am not sure if it is the water causing the problem or not, but to point out the obvious, are you sure your thermostat didn't fail?

I have used UTH's with Repti-temps on tubs without a problem. I currently have a rack with 4" Flexwatt and a Herpstat also without problems. And I have snakes that like to tip over their water, too.

Other then that.. I have no idea what could be the problem. :(

what do you mean there are holes in the bottom of the tubs, and scortch marks on the uths?

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Originally Posted by cinderbird

what do you mean there are holes in the bottom of the tubs, and scortch marks on the uths?

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I mean that literally. One tub (the UTH for this snake has failed 3x - the other has failed only 1x) has 3 tiny holes where it appears that the plastic has melted, and on the UTH, it looks scorched and fried under those holes - like something popped in those places. And then the UTH doesn't work.

I considered thermostat failure, but I've checked out the tub temps with a separate thermometer and probe to make sure the thermostat is working accurately. The thermostat is plugged into the rheostat which is plugged into a power control strip that regulates energy - it's the exact same set-up I had with my tanks; the only difference now is that my snakes are in plastic tubs.

I'm truly using the same set-up before except now I have plastic tubs. Could my sterilite tubs be bad?

Sounds like maybe temperature fluctuations. They get way too high, then low again. They burn through, and by the time you test the temp it's back to normal.

Maybe time to buy better UTH's or flexwatt heat tape (never had a problem with it).

Other than that, I have no idea. Sounds to me like water has nothing to do with it, they're spilling water for one reason: it's too hot, and water cools them off.

Hope that helps.

not sure what your using, but use cobra non-sticky heat mats, they are great or ultra therm, i think the bean farm sells them

what kind of thermostat are you using?

Heavier bowls can help too, if they are heavy crocks they will not knock them over as much.

Sounds to me like your problem may be the rheostat. You should have it 1) thermostat plugged into the wall 2) rheostat plugged into thermostat 3) UTH plugged into rheostat.

I would remove the rheostat and just use the thermostat and UTH to see if the problem goes away. None of my tubs have ever melted or burned up a UTH, and my heaters are coverd with a piece of polystyrene insulation. I think this may have been happening in your glass tanks if you were using the same set-up, it's just now you are seeing it because of the melting, which is why I think it is electrical...

How would the rheostat be causing something like this? The thermostat should still be cutting the power when the heat reaches the set point, regardless of anything else in the setup, unless the thermostat has failed. I'm obviously new and you're obviously way more experience, so I don't mean to usurp that authority, but it just doesn't make sense to me.

And, OP, water couldn't "burn" through anything. It would boil before it got hot enough to burn anything except a few choice chemicals. If it's leaking through the holes, it may be exacerbating the electrical problem that's already present.

I vote bad thermostat. How else could you get temperature spikes hot enough to melt plastic?

Yo should not have holes in the bottom in case water does leak on to the uth! You shoul try leaving an air space under the tub and try using the reostat instead of the thermostat and keep a close eye on temps! You should be using a digital thermometer to measure temps accurately!

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Originally Posted by stevepoppers

How would the rheostat be causing something like this? The thermostat should still be cutting the power when the heat reaches the set point, regardless of anything else in the setup, unless the thermostat has failed. I'm obviously new and you're obviously way more experience, so I don't mean to usurp that authority, but it just doesn't make sense to me.

And, OP, water couldn't "burn" through anything. It would boil before it got hot enough to burn anything except a few choice chemicals. If it's leaking through the holes, it may be exacerbating the electrical problem that's already present.

I vote bad thermostat. How else could you get temperature spikes hot enough to melt plastic?

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I don't have any authority and I don't have the technical vocabulary to explain all the aspects of electricity, but it has something to do with the way the rheostat affects the electrical current that the thermostat needs to operate properly and causes it to malfunction. Because it isn't recieving the proper current, it doesn't detect the temperatures properly. So yes, I agree that the thermostat may need to be replaced, but plugging a new one into a dimmer will most likely result in the same malfunction. That is why, when using a dimmer as a back-up, it should go between the thermostat and UTH, in which case, it will prevent the UTH from over heating in case the thermostat sticks open...

So how thick is your subtrate. What I was thinking is that if you have holes in your tub is because your uth is getting so hot to heat the surface of your subtrate that it is burning the tub itself. Could be way wrong but to me this seems like a resonable answer if your surface heat is correct but you still have holes in your tub but surface heat is ok.

There was most likely not enough air flow between the UTH and the surface you kept it on.

Personally speaking get yourself some flexwatt...you can get it at reptile basics. Then get yourself a herpstat thermostat. Dump the rheostat. Then get yourself new tubs. I would think there is some type of failure with something that is allowing the temps to spike hence the marks and holes on your tubs. This could prove to be lethal to your snakes if you don't do something fairly quickly. I know that the herpstat can come in literally 3 to 4 days. If you call rich at reptile basics and tell him the situation....I am sure he will send you the flexwatt asap.

You cant have the thermostat plugged into a dimmer! The thermostat must be directly plugged in the wall and receiving full power to operate properly! You can plug a dimmer into the uth after the thermostat but not before!

i dont even understand that. i run heat mats PLUGGED DIRECTLY INTO THE WALL on a few tubs, and have never seen anything like that. is it possible that the thermostat could make them hotter than if they were plugged right into the walls?

Bam unless you are temp gunning it constantly you may not even notice your spikes. You HAVE to have a thermostat with any type of heating decive to regulate it. Don't wait until hindsight is 20/20

well seeing as how they all stay pretty contant id say its a safe bet it works, heat mats im pretty sure are designed to be used without a thermostat. im not talking about some flexwatt or something. regardless, the point was ,mine have never gotten hot enough to melt through a tub, whereas the ops did.

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Originally Posted by BAMReptiles

well seeing as how they all stay pretty contant id say its a safe bet it works, heat mats im pretty sure are designed to be used without a thermostat. im not talking about some flexwatt or something. regardless, the point was ,mine have never gotten hot enough to melt through a tub, whereas the ops did.

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But it could. I was saying the same thing as you until recently. I had a tropical heat mat for after the cool down on my cresties. Every single time I checked it it was at 80*F. I set up a thermometer probe on the hot spot that has a fluctuation sensor. Therefore when the temp spikes it saves the info on the hottest temp. Found out my geckos were sitting at about 92*F when I wasn't checking it. Your could have never had this happen but the chance is always there.
And a rheostat before a thermostat in line does t work. Or at least not for me.
On one of my racks I set it so the rheostat wouldn't go above95*F and the thermostat was set for 92*F but my tubs woudlnt hold a steady temp. So out with the rheostat...

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Originally Posted by BAMReptiles

well seeing as how they all stay pretty contant id say its a safe bet it works, heat mats im pretty sure are designed to be used without a thermostat. im not talking about some flexwatt or something. regardless, the point was ,mine have never gotten hot enough to melt through a tub, whereas the ops did.

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Just be careful... UTH's need to be regulated somehow. I plugged in my Zoo-Med 10-20 gallon heater directly just to see how hot it got on it's own and it got over 135 degrees in less then a few hours.

I have a Helix thermostat. It has to go through a power-regulating strip because I live in a house with 1940s wiring; when we first moved in here, the Helix would short everything on that fuse out. I've never before had a problem with it plugged into the strip.

I also have additional, separate thermometers in the tubs to monitor the heat. I monitor the ambient temp around the snakes as well as inside the tubs. I live in So Cal, and the temp in our house in the summer can get pretty high, so the thermometers have an an alarm that goes off if the temp hits over 95 either ambiently or in the enclosures; that way, I can adjust the thermostat. (For examples, when the ambient temp is 95, I can drop the thermostat to 75 and still maintain a nice 85 in the tanks.)

I have air flow both under and around the tubs and UTHs.

The only difference between my set-up now and my set-up 7 weeks ago is the fact that my snakes are in plastic tubs as opposed to glass tanks. I switched because tubs seem so much easier, but this has become such a pain that I'm thinking of just going back to tanks.