Temperature Probe for AC Jr

[zoozilla]

Woke up this morning and found the temperature reading on my AC jr was 20 deg. I verified it against another thermometer which was reading 80 deg. I made sure it was set to Fahrenheit, cleaned off the probe, unplugged/replugged probe from unit, rebooted the AC jr, etc but still no change. Should I troubleshoot further or assume it's a bad probe and replace?

 

Any thoughts?

[YBeNormal]

It sounds like it has failed. You can either try another temp probe to verify that it is bad or buy a new one. Even if the original one is not bad, it will fail eventually so the new one won't go to waste.

[jnguyen4007]

It happened to mine after 1 day of usage. I was able to get neptune to send me a free replacement.

[Rascal]

Bad probe most likely. It is a common problem -- as you can see from a quick search on RC. I don't know why Ranco temp probes seem to last forever but Neptune's probes are notoriously unreliable. I'm on my 3rd probe in a little over a year I think. Supposedly the new ones are much more durable, and this one is definitely thicker than the first two, so hopefully they have solved the problem.

 

For redundancy I use a Ranco on my chiller as a back-up. The AC is programmed to turn on the chiller at 81, and the Ranco is set for 80. So even if the AC is reading 20 degrees high, the Ranco will shut the Chiller off when the temp hits 79. I do the same thing with the internal controllers on my heaters.

 

The following programming lines suggested in a previous thread here are also a good idea:

 

IF TEMP > 110 THEN COL OFF

IF TEMP < 060 THEN HET OFF

 

These will stop your tank from cooking or freezing just b/c your probe goes out.