Is Your Ranco Temperature Controller Accurate?

[dooleyb]

Just wondering if the Ranco temperature controller is accurate? I installed one last evening and the temperature is 3 degrees different than what the tank was measuring. I am using one of the Big Temp and it was saying that the tank's temperature was 81.5 degrees. The Ranco would only reach 78 degrees. I had the ranco set to turn on the heater at 79 degrees and turn the heater off at 81 degrees. Got up during the night and the temperature in the tank was 82.3 degrees. Right now it the ranco is set to turn the heater off at 78 degrees. Can someone give me some pointers here? Did you have to calibrate your Ranco and how did you do this? How do calibrate the tanks temperature?

Thanks,

Bill

 

[Nabber86]

Maybe your Ranco is accurate and your tank thermometer is wrong.......

 

[dooleyb]

Nabber86. You may very well be right. I am going to run some test tonight. I have been doing some investigating and find that the Ranco is very accurate. I am going to put some water in the freezer and get it to start freezing which should be very close to 32 degrees. Then test the probe on both the Ranco and the Big Temp.

 

[RGibson]

<a href=showthread.php?s=&postid=7170636#post7170636 target=_blank>Originally posted</a> by dooleyb
Nabber86. You may very well be right. I am going to run some test tonight. I have been doing some investigating and find that the Ranco is very accurate. I am going to put some water in the freezer and get it to start freezing which should be very close to 32 degrees. Then test the probe on both the Ranco and the Big Temp.

take a large glass of water add ice and mix will be at 32 deg chech the control tem this way.

 

[dooleyb]

Thanks folks. Last evening I used the glass of ice water to test the temperature probes on both the Big Temp and the Ranco. The Ranco tested at 33 degrees so I think it is accurate. The big temp tested at 35.8 degrees , 2.8 degrees higher than it should be. Which this means that my tank's temperature has been running 76 - 79 degrees instead of the 79 - 82 degrees. Do you folks thing that the 76 - 79 degree temperature is ok? Most of the time it will be 78 - 79 but sometimes may dip to 76 - 77 especially in the Winter.

 

[elephen]

Mine used to be accurate till it burned down about 1/2 my fish room.

Word to the wise, keep them away from anything flamible and keep an eye on them.

 

[dooleyb]

Ouch! What went wrong? Was it a faulty temperature controller?