Spa Only Gets Warm, Not Hot

[lodi]

I have a four year old Jandy JXi Spa heater (2nd one). It gets the spa to about the low 90s but will not heat up all the way. Everything else works fine. I have heard that waterflow issues can cause this. Seems like waterflow is strong at the main outlet in the spa, if that's an accurate way to measure it. Do I have a thremostat issue? As always, thanks in advance for your help.

**edit, corrected model of Spa Heater.

 

[ajw22]

I cannot find any information about a Jandy HS4 Spa heater.

Please post some pics of your equipment so we can see what you have.

 

[lodi]

I have no idea where I got that from. Its a Jandy JXi. Sorry! I will update the original post.

 

[ajw22]

Is the JXI heater connected to any automation?

 

[lodi]

None other than the Jandy mobile app.

 

[ajw22]

None other than the Jandy mobile app.

There has to be some automation between the JXI heater and the Jandy mobile app.

The JXI heater does not connect directly to any app.

 

[lodi]

I guess that would be the iAquaLink system. It has a wireless connection at the pool equipment. Then I connect through the mobile app or a web browser.

 

[lodi]

I haven’t changed any values on iaqualink Automation UI. I just went in and checked to ensure this to be the case. I will say that the spa will read at 104 on the mobile app but the water is probably 20° cooler.

 

[ajw22]

What is the heater temperature set on the JXI heater control panel? It needs to be set to the maximum of 104F.

 

[lodi]

It is. I think I’m gonna replace the thermostat and see if that works. Everything else seems to be in order.