South Florida inground pool and whirlpool owner, Hayward controls, with 1 year old Jandy LXI heater

[Logan005]

I was replacing the igniter today and found this site. We use our pool and hot whirlpool everyday year round. We have lived in this house for 8 years and originally had a Hayward heater that started leaking. so we replaced it with the Jandy lxi, unfortunately the Jandy never heated the water over 101 deg. according to our Hayward remote and a thermometer in the water, yet the control panel on the Jandy says 104deg.
I never got around to figuring out the problem. Hopefully I can get help from someone here. We live in a Unique home with two outdoor rooms that surround the pool and very much enjoy the outdoor life. I you have seen this temperature issue and have knowledge please let me know. Meanwhile I will be waiting on my new igniter. Best regards Logan...

 

[ajw22]

Welcome to TFP.

You need to remove the temperature sensor from the heater and test if it is reading correctly. You may just have a temperature sensor that is a bit off and can be replaced.

Your manual is here --> https://www.royalswimmingpools.com/JandyLXiManual.pdf

See pages 50 and 53 for part 32 the Temperature sensor.

The temperature sensor is a 10K thermistor and you need a multimeter to measure its resistance. You then lookup the resistance to determine the temperature using this chart...

104 degrees is 5,326 ohms.

I would remove the sensor and bring it into the kitchen along with a known accurate thermometer and put it under the hot water tap. Watch the resistance as it heats and see how it corresponds with the actual water temperature. If it is off then replace the sensor and see if you get a more accurate one as a replacement.

Temperature Sensors - Further Reading

www.troublefreepool.com