OK, so I just installed a pair of visi-therm deluxe 300w heaters in my 200. I know that the indicator on the front when you're setting the heater can't be completely trusted, so I set it at 80 (the tank WAS at 82). This morning I get up and the tank is at 84.5. (!) So, I turn both heaters down a couple of degrees, go to work, and come home and it's 85.2, with one of the heaters still warm from recently being on. WTF gives here, I'll accept some inaccuracy here, but the heaters are now reading 76 deg, and the tank is at 85. Am I supposed to believe that this is the state of technology? we still can't make a cheap thermostat?
Heater Hysteresis and inaccuracy, WTF!
- Thread starter cvermeulen
- Start date
Volenti;1023843; said:
OK well I disagree with you on two counts... microprocessors are great, but they are the largest source of engineering laziness ever to strike the world. there is no reason a mechanical feedback control can't control something to within a fraction of a degree, nevermind 10 degrees.
Second, microprocessors are CHEAP, but that's another story.
I think the real problem is just the way the system components interact... the knob controls a screw that adjusts tension on a bimetal strip, and also moves the little plastic indicator that tells you your setting. The stupid bimetal strip tolerances are such that they can never be controlled tightly to what the indicator reads.
Really, I'd be much happier if they ditched the stupid temp indicator and just put an arrow on the knob that said up/down. What use is it putting a graduated temperature setting on the thing if it doesn't work?
ok, done ranting for a few minutes.
I have 2 top of the line (i for get the model) Rena 300w heaters in my 150 both are at 72*f and my tank is at 78-79*f.... I had them at 76 and my tank was 86*f which is why I was mis reading my old thermometer...
the temp scale on the heaters is a 'new' thing.....they used to be all hotter/cooler only......good ole days
We still have the same problem with some of the cheaper thermostats for reptiles, so I feel your pain there. The only way you can get an accurate measurement is if you invest $100 or more into the product.
This is why I prefer to use Ebo-jager/Eheim Jagers. The numbers on the top can be inaccurate, but all you have to do is calibrate the heater, and you are back up and running.
I have ONE visitherm 250w in my 125g, and I have to say its best damn thing I've ever purchased for my tank. Its set to 78 in my basement and my temp reader is reading 78.2 CONSTANT. I think YOURE problem may be your room is warmer than your heater is set at. I know my 55 gallon in my living room is reading around 86 in the day and drops to 79 at night. You bought a heater, not a climate controller. Do colder water changes if its a problem.