My jacuzzi hot tub is displaying error code FL2. The temperature is at 100 BUT I have it set at 85, it won't go down. The mother board was replaced last year for the same code. Any ideas how to fix this?

test heater for failure and 382 ? code this is owners manual and codes foe jacuzzi j315 https://www.manualslib.com/manual/1263595/Jacuzzi-J-315.html?page=30#manual https://www.thecoverguy.com/backyard-blast/jacuzzi-hot-tubs-error-codes-information/ https://www.fortywinksonline.com/localimages/jacuzzierrorcodesexpalined.pdf

Sounds like a problem with the thermostat.

An F2 error code means usually that you have a flow issue in your hot tub or you have a part malfunction. The best thing to do with an F2 error code is to go through a trouble shooting diagnosis. Start by cutting the power and letting the unit cool down and then do a reset of the equipment. If that does not fix your issue then do a water flow check, clean your filters, release air locks, remove debris from your intakes and returns. If your problem still remains look to replace or repair fuses, heater elements, or your circuit board. I hope this helps. http://www.thecoverguy.com/backyard-blast/f2-error-code-trouble-shooting/

Hello, and thanks for the question. Your error code is actually "SN" not "5N" but they are sometimes difficult to discern on the LCD topside display. The SN error code is for a Non-functional High temperature sensor which automatically kicks the heater off and trips the breaker. You can purchase new sensors for $75-$85 (it could be more, my pricing index is quite a few years out of date) I'm not sure where the sensor is located in that particular tub, although it is most likely in the heating canister. Make sure the power is off at the breaker before attempting any tub repair. if you have shut-off valves to the heating canister you may not have to drain the tub, remove the heating can and replace the sensor you will have to plug/unplug the sensors from the power pack/circuit board. I hope this helps =)

Located behind the access panel there is a grey box that is the spa pack. Open that up with the 2 screws on the top of the pack. There is a small glass fuse on the circuit board. One of those fuses is most likely blown. If that is not the culprit you need a new topside control. More than likely it's the fuse.

Here is a link for you to resource that error code.
click that link and scroll through them until you find your error code.

Rod
US Parts Center

Jacuzzi has the manuals online if this is a jacuzzi brand hot tub.
http://www.jacuzzihottubs.com/request-brochure/download-manuals.html

This is a bad main board issue