Water temp at 104

[Julie Kirk]

Caldera spa 2016. Water temp has been reading 104. Ambient temp has been about 95-100. Temp set to 98. Seems like filter icon is in a lot. I put it into Econ. Gonna drain and clean. Could the hot weather be affecting the temp? Not in full sun all day. Cover is good.

[mrwrick]

If my covered spa sits in full sun half the day when ambient temp is high 90's and the spa thermostat is set low, almost off, the spa will reach mid-90s. If the thermometer sits in the sun in spa water that is in 90's it will quickly rise higher than spa temp. Don't underestimate the power of solar. That is not to say something else might be going on, like your temp setting is off, as in  not accurate anymore.

[Cusser]

My spa is in Phoenix on the patio, so covered from most sun.  Some afternoon sun can hit it.  When my kids were little and we used it as our "swimming pool" in the summer, had to leave the spa cover off a night or two per week to let water evaporate to cool the water enough to use, went well over 104F.

[NO1UNO]

It's likely just the weather but if you want to check it, drain some water out (it won't take much) and add fresh water from the hose. This should drop your temp down below the 104 you're currently reading. Set your desired temp to 2 degrees above the whatever the actual temp is on your display (ie. if your cooled temp is 98, set your temp to 100). If the heater/heater light kicks on and off on schedule then you're good. The whole process takes about 40 minutes. 

Again, it's probably not a problem. Good Luck.

[JaMas]

I have my Spa set to 98 and it's currently reading 100.  Spa is in partial sun for half the day and ambient temperature has been in the low to mid 90's.  I'm assuming that between the sun and whatever heat the pump generates during the filter cycles is raising the temperature above its current setting.