Temp showing way higher then what set at

[Jostudly]

I am wondering if my heater is working properly. We had a outside temp today of 28c with 31c humidity. I lowered the temp of my hot tub the day before to 30c but my display is reading 37c. I also checked the thermometer in the tub and its 37c. Is this normal to have the tub reading 7c more then the set temp on a hot day? I figured it would only be out a couple degrees. I lowered the temp because i had a overheat issue a week ago where the temp climbed to 44c and had to replace the whole spa pack. Do many of you who live in the south have to turn your temp down much on hot days?

[The Wizard of Spas]

I assume you're not in the US as you're reading C vs F.  So I ask- Is it summer there?  These hot tubs are well insulated and covered so if it is hot where you live and you have the temp set low, that wont necessarily cool down the tub.  Think of it this way- Your tub is so well insulated and covered its like wearing a winter coat in a heat wave.  Of course the temp is going to climb. 

If this is the case, try propping open your cover a bit to let the tub vent.  I just place a tennis ball in the corner under the cover to allow some heat to escape and for the water to breathe. 

Again-  Tubs have heaters that heat the tub but most don't have anything to cool the tub down.  Does this make sense? 

[Jostudly]

I live in NB Canada and we are having a heat wave with almost 40c humidity. I asked my dealer and they said the temp should only vary a couple degrees not 6-7 degrees warmer. They said it may be a issue with the heater and are sending a tech next week. The tub should not continue to heat if the set temp is lower so i don't beleive just opening the cover for a few hrs will make a difference if not would probably increase the temp.

[The Wizard of Spas]

40 C translates to over 100 F.  That to me would indicate that the tub is just well insulated and its getting pummeled by the heat.  Some pumps do have standard settings where they will run just to turn over water and that can help heat the tub.

Yes- It could be a hi-limit switch issue.  That could be it.  But I'd leave the cover propped open a smidge to let it vent just to see if there is a change in the water temp.  I'd hate for you to get charged a service call for something that isn't an issue with the technical aspects of the tub.

[Jostudly]

I turned the temp down to 25c and now the tub displays a temp of 35.5c. I have a tech coming at no charge as it is still under warranty. If he cannot find anything wrong i will try keeping the cover open a little at night but did not think i would need to do this as the heater should not turn on if the temp is too high.

[Hottubguy]

My tub is set at 80 for the summer.  We use the pool more.  It's been high 90's here so for the hell of it I checked the temp.  Its at 97

[Jostudly]

Mine is set to 77F but is really at 98F. Will see what the tech says tomorrow

[dlleno]

I noticed that my tub temp will climb above the heater set point in the summer as well.  note that things don't heat up just because they are insulated or covered, they heat up because there is a source of heat and the insulating cover helps trap that.  three sources of heat are:

1.  the sun.  even with an insulating cover, the sun baking down on the exterior of the tub imparts energy into the water in the form of heat

2.  the cycling circulation pump.  you don't notice this in cold weather because pumps transmit very little energy to the water, but they to contribute a non-zero amount which will tend to raise the water temperature.

3.  ambient temperature.  if there is very little temperature difference between the air and the tub water, then it takes very little energy to heat the water hotter than the ambient air. 

[Jostudly]

My dealer wants me to open the cover at night and try economy mode before a tech comes out. I can set the economy for a specific time and up to 24 hrs. I put it at 6pm for 24hrs. Does this mean the heater will not come on even during filtering and only if it drops below my set temp of 25c ?