I can't locate the high limit sensor on my Artesian spa that has a Gecko controller. HL error code is present. I think I have good flow thru heater, i even ran pumps without filters so I don't think there is a restriction. Where is the high limit sensor located, on the heater tube? I think i found the temp sensor with a pin connector that hitches to the spa pack circuit board, but am unsure where the hl sensor is. Thanks in advance!

High limit sensors will be found as near the heater element as possible, so look for it on that tube.

Thanks charger1, I found the high limit sensor on the heater tube. This sensor is made of foam material with wires inside. One end is resting against the heater tube in a slot and the other end seems to be connected to the circuit board. On the circuit board end there are no connectors, it seems to be soldered directly to the board. Is this sensor replaceable or is it an integral part of the board? I haven't seen any sensors like it on any spa parts suppliers sites. thanks in advance.

I'm not sure I've seen what you are describing either. Perhaps you could post a photo?

charger 1, here is a picture of a like Gecko circuit board. The high limit sensor is on bottom right with yellow tag on it It looks like it might be a part of circuit board as no other sensors are shown.

i'm sorry but I haven't encountered that design in my experiance, but with that pic, perhaps another tech may strike on something I missed.

Good luck!

I am having the same problem and wondered if you or anyone has replaced this "soldered in" hl sensor? I am hoping I do not have to replace the whole control unit due to one bad temp. sensor.

That is a Gecko PC board with a soldered on HL sensor. If you have finesse with a soldering iron, you can replace the sensor only. If not, the PC board must be replaced. Good luck.