H-40 Salt Chlorine Generator powers on and off constantly

[kgiryes]

Hi all, our Hayward H-40 Salt Chlorine Generator used with a T-15 cell powers on and off about every 10 seconds. "Power" and "Generating" lights are on for ~10 seconds, then off for ~10 seconds, over and over, even when on super chlorinate. Also the salt level hasn't changed at all in weeks, even though I know the reading is off. It's consistently 3200, when I tested with my dropper salt kit, it was coming in at 2600 (too low, I know.)

Diagnostics:
74
3.3 when ON, slowly up to 21 when OFF then back ON.
.04 when ON, 0 when OFF
80%
-0 Always
AL-0
r-1.58
T-15

Thank you for any thoughts

 

[JamesW]

Probably a bad thermistor.

Hayward Aquarite SWG - Further Reading

www.troublefreepool.com

 

[JamesW]

Failure Modes
The thermistor is pretty much the only thing that fails in the AquaRite power box. It stays hot the entire time it's generating. However, it's only needed during the first few seconds of operation.[23]

Symptoms of a bad thermistor include no power and chlorinating light, no power to salt cell.[24]

When the thermistor begins to fail, the voltage gets erratic.[25] Zero volts points to a bad thermistor.[26]

The thermistor used to limit inrush current (the "big black disc") usually blows after a power surge, typically brought on by a storm or utility glitch.[27]

Diagnostics
Usually you can see cracks in the coating on the thermistor indicating it’s bad. Some have looked normal and couldn’t find any cracks - but they were bad. Don't bother testing them because in order to access the thermistor...everything else is removed, it wouldn’t take much longer to just replace it.[28]

Thermistor Replacement
Thermistor is a AS32 2R025.[31]

You can also use a SL32 2R025,which is easier to install.

SL32 2R025 Ametherm | Circuit Protection | DigiKey

Order today, ships today. SL32 2R025 – Inrush Current Limiter 2 Ohms ±20% 25 A 1.220" (31.00mm) from Ametherm. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

The part cost is $2.50 and the repair takes about 15 min. You can cut the legs of the old one and solder the new one to them at a 90 degree angle standing away from the board. It's easier to do and allows for better cooling.[32]