Apex temp probe

[Surfside74]

I have an apex jr. and the temp probe is in the sump. The temp on the display constantly fluctuates rapidly all within the same degree range. Example: it will say 77.6 then 77.8 then 77.5 all within a few seconds. My program is set to turn heater on at 77 and off at 78. My heater turns on and off a lot throughout the day as you can imagine but i feel that is due to so many temp fluctuations. I bought the unit used and this has been the case since i got it. Anyone have any ideas? Is the probe bad you think? Any help would be great

 

[tastyfish]

I have an apex jr. and the temp probe is in the sump. The temp on the display constantly fluctuates rapidly all within the same degree range. Example: it will say 77.6 then 77.8 then 77.5 all within a few seconds. My program is set to turn heater on at 77 and off at 78. My heater turns on and off a lot throughout the day as you can imagine but i feel that is due to so many temp fluctuations. I bought the unit used and this has been the case since i got it. Anyone have any ideas? Is the probe bad you think? Any help would be great

Sounds like either a faulty probe (loose connection, broken wire etc), corrosion on the connector plug or electrical interference.

I would:

- Check for obvious breaks/damage to the wire
- Check and clean the plug and socket for salt creep/corrosion
- Ensure the wire is well away from other cables, particularly power cables and pumps.

Hope this helps

 

[Oberst Oswald]

On something that is as important as tank temperature it my be wise to get a new temp probe ($30.00). Your heaters will have a shortened life by turning off & on with such frequency.

 

[Surfside74]

On something that is as important as tank temperature it my be wise to get a new temp probe ($30.00). Your heaters will have a shortened life by turning off & on with such frequency.

Second probe. No change. Moved probe to overflow. No change. Any ideas ?

 

[Oberst Oswald]

Try giving your apex program a wider spread something like on at 77 and off at 79. If this stops the fluctuation slowly rise the programs 77 to 77.2 and lower the 79 to 78.8 if possible. Keep on doing this until the fluctuation starts up again, than lower or rise until stable. If this don't give results change the water location of probe to different parts of system. Maybe probe is too close to heaters, motors, air bubbles or flow. Other than this I'm at a lost on what your problem might be and wait for replies from the Apex experts.