Faulty chlorine/ORP sensor?

[rileypop]

Hi all, first post and hoping you can really help me.

I have a Hurlcon RC8 unit with an Astral ORP chlorine sensor.

Lately my chlorine levels have been really high with out actually changing any settings. The tests every week for the last 4 weeks have been above 9.0 free and combined.

The ORP set point is set at 650 and has been set at this for as long as I can remember which makes me wonder if the sensor is faulty.

All other test levels are within the acceptable range except stabiliser which is low and needs topping up every week.

Any advice would be much appreciated.

 

[VinceL]

I have the Hayward Sense & Dispense with pH and ORP probes. I've read that these probes will only last for 2-3 years. I am still using my original probes from 2012. I clean them a couple of times per year.

The pH probe continues to provide readings that match the results of my water testing within .1

The ORP probe has drifted from its original readings. In the first couple of seasons, I let it automatically control the SWCG with an ORP setting of 650. My water testing reflected chlorine levels of 3-4 ppm which is right where I want it in my fiberglass pool. For the past couple of years I have set the SWCG for a timed % rather than relying on the ORP since leaving it at 650 was causing the chlorine level to get too high. Maintaining my chlorine at 3-4 ppm now leads to the ORP sensor reporting a value in the low 500's. But, I do find that if I see the ORP reading creep up, when I test the water, I will find that the chlorine has gone up. So, the ORP sensor is providing some value to me. Maybe if I replaced it, I would be back to its original readings. Well, a new sensor costs nearly $300....I can live with what I have.