OH issue

[Flukeman]

Actual water temp 91 F.

Display rapidly increases to 112 and trips out giving OH code, then HL code a minute later

Any ideas?

Brand new filters

All jets under water, and pumping

just replaced pump, and filled

Thanks in advance

Edited November 29, 2023 by Flukeman
More detail

[waterbear]

Make and model would be a good starting point.

[CanadianSpaTech]

If it is a Jacuzzi or Sundance Spa post the year of manufacture. There is a recall on Temp sensors.

 https://www.jacuzzi.com/en-us/recall.html#

Jacuzzi or not your issue is likely with the temp sensor. 

[RDspaguy]

Most likely the heater is running without flow or the sensor is touching the element. Remove filter. Check heater pump, which is often a different pump than the jets, for flow. Check to verify power is turning off to the heater as a stuck relay will cause it to do as you describe as soon as power is turned on.

[Flukeman]

The spa is 21 years old. My owners manual does not tell me manufacturer. I thought it was a Sundance back then, but over the years I have replaced parts and the designation used was Gatsby CS6237. I have replaced main box, heater, and topside control panel over the years. I have two jet pumps and a circulation pump off the heater.

Yesterday a friend tested voltages on the heater, readings were 236v. Circulation pump is working, tub heats up as it should to set point, then just ticks off degrees to 112 and trips. When I say heats as should I mean slow and steady over time. But once it reaches the set point(102) it just starts ticking off 102 to 112 in seconds.