temperature probe

[Chrisrush]

Is there a way to tell if the temperature probe has gone bad? My tank has been running at 80 (+/- .3) degrees for the past 6 months. Yesterday, it spiked to 80.7 and this AM, the temperature is 81.4. Nothing has been changed in the past 2 days (such as add another pump, etc.) and the heater is not currently on.

What is the life expectancy of the temperature probes? I have a second thermometer, but I'm not sure that I trust it's readings.

[AQD_ottawa]

Ambient rise in air temp, humidity of room, heater coming on when you are not about.

Never has a single temp probe (or any probe for that matter) give issue, so it is going to be enviromental, but you can test the probe against a mercury thermometer taking into account toleremce differences of +/- 2 degrees