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Ok don't just start bashing....

oldsnow

oldsnow

Hrmmmm........
I've already searched threads and haven't found an answer, so I'm posting. has anyone had issues with a Home Depot dimmer being harder to stabilize? I have a Lutron rotary dimmer from Lowe's on Spot's 29 gal. controlling a 10-20 UTH. On Thumper's 55 gal I have the large UTH and have been controlling it with a Home Depot rotary dimmer.

I had Spot's temp's stable within 6 hours, but Thumper's will be all over the place. I started with it all the way down and slowly worked my way up. To begin with, every time I would turn it up I would let it set for 30 mins to an hour for the temp to stabilize and it never moved from 78-79 degrees. Then I bumped it up again (and by bump I mean turn until I feel it move and STOP) and the temps shot up to over 90 within the next hour. Bump it back down and it's back to 78....... Obviously I will be going to get another Lutron dimmer to replace the Depot one, but has anyone else had this issue? would the fact that it's a 50 gal UTH make it harder to regulate than a 20 gal?

Any help would be great. And yes I'm sure its wired right... I've done electrical work for over 6 years.
 
I have several of those dimmers and had the same problem. I used them on various sized mats, so I'm not sure if it's the size or just the fact that it's not as sensitive as one made for an actual heat source. I finally gave up and got a reptile rheostat and haven't had any issues with them.
 
Mine does about the same thing. But I when my tank temp spikes, I notice that the heat is on or just cut off. It's at it's coolest very early morning before the heat cuts on. It will say 81.5 when I get up in the morning and sit at the computer and after the heat goes off, it will usually say 84.5.

Just keep in mind, it restricts current, not control temperature. Environmental changes can play a big part in the change of the temperature.
 
_skittles_ said:
Mine does about the same thing. But I when my tank temp spikes, I notice that the heat is on or just cut off. It's at it's coolest very early morning before the heat cuts on. It will say 81.5 when I get up in the morning and sit at the computer and after the heat goes off, it will usually say 84.5.

Just keep in mind, it restricts current, not control temperature. Environmental changes can play a big part in the change of the temperature.
Click to expand...

My house stays at 73 constantly due to my little ones getting cold so I know its not that. I'm wondering if I'm hitting the low current threshold on the UTH and at its lowest possible setting it is just too much..... Possible?
 
Remember that a dimmer switch has nothing to do with temperature. It is basically a variable resister that resists the flow of current to the UTH. The mathematics of electricity says that Voltage = Current X Resistance. So as the Resistance of the variable resistor goes up, the Voltage at the UTH goes down. At a lower Voltage, the UTH produces less heat.

What you are experiencing right now is a fluctuation in the line voltage coming into the house. I would imagine you are finding your UTH temperatures to be lower in the morning and higher mid day and afternoon. This is because everyone just woke up and turned on the coffee pot, took a shower, made toast, and turned on the morning news. Once the kids are off to school the demand on the city will go down and your snake will warm up.

The advantage to a thermostat is that while it controls the voltage it regulates it in connection to the temperature.
 
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_skittles_ said:
It would be nice if a home could stay a constant 73!
Click to expand...

It's absolutely lovely to keep it set at 73, and its a nightmare monthly when the bill for the gas heat comes. Especially with the 2 week cold snap we had down here a little while back
 
That cold snap was a nightmare here. I had to struggle to keep things regulated in my tanks.

It took me a week of testing in a set up but snake empty tank but I finally got a good balance. I'm going to pick up 2 thermostats when I get my tax refund and stop fiddling with dimmers. Dimmers are great but I agree with what Wade was saying about power flows and such.
 
Ok, let me try this again, as maybe I didn't make my question clear enough.

Spot's tank:
29 Gal. glass
10-20 Gal. UTH
Lutron rotary style dimmer
ZooMed digital thermometer with probe on glass over UTH

Temp's are constant 83-84 F no matter what time of day with ABSOLUTELY no adjustments.

Thumper's:
55 Gal. glass
50-60 Gal. UTH
Home Depot rotary style dimmer
Zilla digital thermometer with probe on glass over UTH

With dimmer at lowest position temps are 79. With less than a 1/16 of a turn, temps shoot to 90's. Bump the dimmer back down and they go back to 70's.

I was asking if anyone had had issues with depot's dimmers or if I just got a bad one.

I know I can get a thermostat and get nearly constant temps, but don't have the money until the end of next week and would like to be able to regulate my temps to at least 80 while I have to wait on the thermostat. I already had plans on buying 3 thermostats so when my rack is up and running I will be able to have one on there as well as both "display tanks".

I fully understand how room temp can change the UTH temp when using a dimmer to regulate and I also understand the concept of how a dimmer works.
 
oldsnow, I have a plug-in style lamp dimmer from Home Depot, sliding style (not round). It works well for me; I rarely have temp swings over 3-4 degrees unless the room temperature does something weird.

So while I can't tell you if what you're experiencing is normal, I can tell you that the plug-ins work well for me. They're only about $10, if you'd like to try.
 
Thank you Emily, for answering and not giving me a science or a math lesson. I will try that since $10 is a lot easier to explain to my wife than $100 or so.
 
I started writing a long winded reply to you hours ago, but got timed out by the forum. I'll try to type this one faster:

I would recommend the $10 Leviton sliding dimmer from Home Depot rather than the rotary style that you mention.

I have used botha black one and a while one, and they are rather identical in terms of how far you slide it to get the same temp, so based on the two samples I have tested, they are rather consistent.

Also, I keep mine in the lower 1/3 of the total range. A millimeter of movement can cause a 3 degree change in temp...so you have to move it in fractions of a millimeter if you want to make 1 degree changes.

This is hard to do. The other day, i wanted to drop mine from 86 to 85 degrees. I went too far, and down to 79 degrees. A slight bump back up, and I was at 86 again. the important thing is that I had plenty of room on both sides of the switch. Unlike the rotary you mentioned, the slightest bit of current caused you to spike to 90 degrees. With the Leviton sliding rheostat, I still have about 1/3 to 1/4 of the total range left on the cold side for adjustment.

This morning before I left, i dropped in a fraction of a millimeter...to see if I can get it to 84 or 85. We'll see when I get home what it gets to. I don't have a snake in there right now, so I can experiment.

I would suggest getting the sliding style of Leviton dimmer for $10 from Home Depot. ALso, get the white one. It will be easier to make marks on once you get the temps set.
 
oldsnow said:
Thank you Emily, for answering and not giving me a science or a math lesson. I will try that since $10 is a lot easier to explain to my wife than $100 or so.
Click to expand...

I think you'll find it works for you, especially with a steady room temperature. Let us know how it works out.

As for math, I'm an abysmal failure, so I couldn't even begin to go there (nor would I want to!) ;)
 
oldsnow said:
Thank you Emily, for answering and not giving me a science or a math lesson. I will try that since $10 is a lot easier to explain to my wife than $100 or so.
Click to expand...

Gee, I'm sorry if my answer was too complicated, your age indicated that you were and adult.
 
Wade... Didn't mean to rub the wrong way, it wasn't my intention as I am still a newcomer to the board. Just that in my OP I stated that I've been doing electrical work for wuite a while so wasn't expecting voltage lessons. That was why I added that in the OP.

Again, didn't mean to offend, guess it sounded wrong now that I reread it.
 
My thought is that it may be harder to move a rotary dimmer the slightest possible amount compared to one of the sliding ones. I have one of the sliding ones on one of my vivs & haven't had much difficulty with it. So my guess is one of two things:

1) you got a bad dimmer -- you could test this with a plug-in lamp with incandescent bulb & see if it changes wildly with tiny turns of the knob
2) the sliding type is better -- they are about $10, as you said, and until refund time, that's more manageable

I think Nroc's right -- get the sliding type!

Good luck!
 
I use the sliding style dimmers from Home Depot and never had much problem. I have noticed fluctuations at times - mainly as the room warms and cools. But then I don't CONSTANTLY monitor the temps - just now and then.

I never really knew about the electrical stuff - I heard some of that stuff before, but never totally understood it. I never thought about it being affected by the total use of electricity on the grid at any given time. Thanks for the info, Wade!
 
oldsnow said:
Wade... Didn't mean to rub the wrong way, it wasn't my intention as I am still a newcomer to the board. Just that in my OP I stated that I've been doing electrical work for wuite a while so wasn't expecting voltage lessons. That was why I added that in the OP.

Again, didn't mean to offend, guess it sounded wrong now that I reread it.
Click to expand...

No offence taken. I was too sharp with my reply. I put the mathematical equation in there because it makes it easier for some people to understand. If V = CR some people can see that as R goes up V comes down. For others it doesn't help.
 
I have a sliding type dimmer, but even at its very lowest point, it allows my smallest heat mat to get too hot. Kathy and Betsy, what sizes do you find these work best on? Kathy, are you using these for a rack as well?
 
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