Heater problem, won't heat past 95 degrees

[blofquist]

South Seas Spas hot tub. Around 300 gallons. Have had the spa for abut 6 years. Current problem. For the past week the GFI has been tripping on a random basis. I started turning off the main breaker. Then turning back on a few hours before I wanted to use the tub. That has morphed into a different problem. The GFI has stopped tripping but the hot tub won't heat past 95 degrees. Temp is set to 102 degrees. I just want to confirm that it sounds like I need to replace the heater. I have had tubs in the past where the heater failed. But when it did, it didn't heat at all. This seems a little strange.

Thanks,
Brian

 

[kimkats]

I don't know the answer but here is a bump to get it in front of more eyes.

 

[blofquist]

Thanks!

 

[blofquist]

Still working on the problem. Both pumps running eventually trips the GFI. If I run only the pump cycling through the heater the tub will stay on. But, still having the problem of getting the temp over 95 degrees. Checked the voltage between ground and both of the connections on the heater. Both are approx 120 degrees. So likely not the heater. Could it be a temp sensor?

 

[Swampwoman]

Check to see if the tripping is throwing it into “Econ” mode instead of standard. Mine is a jacuzzi but that’s what it does when tripped and I have to reset the keypad to standard to get it to heat.

 

[blofquist]

When it clicks off. I have to turn the GFI off and then the main. Wait a bit and turn on the main, then the GFI. Tub screen says PR. Have to cycle it back to STD.