Spa continues to circulate and heat past set temp

[hopdigity]

I have a 1999 Marquis Coastal Series tub. Everything seems to work just fine, except after the tub reaches the set temp, the heat light turns off and it continues to run beyond the set temp. It's gotten up to 106 while set at 80 and then I just turned it off. Also, the filter cycles seems inconsistent. I have it set for 1 hour 2x/day, but it seems to run more than that.

When the tub was at 106, I measured it with another thermometer and it was 106. The fact that the heat light turns off when it reaches the set temp tells me the thermostat is okay.

Does anyone know what may be causing this and are there any troubleshooting ideas? Thanks!

[MaryH]

Does your topside panel have a light or indicator on it that comes on when you push the jets button? Is that light on during a filter cycle? If not is that indicator on? I am trying to determine if it is in the topside panel causing the pump to continue to run. Can you operate the pump on both speeds with the topside panel?

[hopdigity]

The only indicator on the panel is the "heating" light. That light turns off after the set temp is reached, but the pump still runs. The circulation pump only runs at one speed, but I assumed one of the speeds was burned out. I have to push the button twice to turn it off, which tells me one speed isn't working.

[MaryH]

Hi if this is the pump used to heat the water with on low speed and low speed is not functioning this is probably why you are getting the flo error code.

[hopdigity]

UPDATE: The filter cycle seems to be fine now. However, I just checked the temp and the display says 107, but I just measured it and it is actually 99.