Permanent $1 fix of ERROR 91 LOW SALT and ERROR 92 HIGH SALT

This article is about fixing SALT LEVEL ERROR, while keeping all other function of saltwater system working, like automatic changing of polarity to keep electrocatalytic cell clean, timing and copper dispensing. I assume you came here, because you already cleaned the cell by vinegar and your salt level in pool is correct, but you still getting LOW SALT ERROR.

So, please make sure you are not fixing dirty cell or wrong salt level. First, keep your cell clear and your salt level at 3000-3500ppm.

This is how clean cell looks like. If you have this and your salt level is correct, then continue to fix.

You can read on internet about few fixes. I have tried all, none of them worked permanently or kept the system fully working. First two solutions suggested to connect copper electrode parallel to the cell or reverse polarity. I have tested both, and it worked. But just day or two and then bam, LOW SALT ERROR again.

So another solution was to connect the cell directly to the power. Well, this has several side effects. It did not solve the error, it just keep cell runing. So if you turn the unit on, you will still get annoying beeping sound and if you turn it off, cooling fan will not run. And - the most important - even when unit is on, the polarity changing will not work, timing will not work and copper dispensing will not work. So, this was my last option, if everything fails. Furtunately I do not need it anymore.

I was thinking, how it works. It actually measures the salt level by measuring water resistance. The current going through water is generating voltage on shunt and this is measured. Like this:

So the idea is to stop measuring actual level of salt and use fake level instead, set by user. Like this:

This would wipe out the ERROR 91 and ERROR 92 once and forever. And... it actually WORKS!

It took me few days searching and trying internet hints and finally finding my own, so here is the time to consider buying me a beer, because you will fix this issue forever!

Disconnect the unit from power grid and pool hoses. Do not forgot to CLOSE your filtration unit and pool jets, just to make sure water will not come out. Open the cover by unscrewing four screws. Take photo how to connect all wires back or mark them by numbers. Disconnect all wires and remove the board.

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Locate JP1 wire connection. This is the measurement line. Cut it on the left side.

The idea is to put little adjustable resistor here, which will fake the salt level we need.

Buy 100K ohm adjustable resistor like this:

or

See the image bellow, how it works. We will use the wiper to set the fake level. We will connect low level to left leg and high level to right leg.

You have to connect the variable end (the leg in middle or the one in the opposite to two legs) to the right side of JP1. Connect right end to JP2 and left end to FLOW+ terminal.

Just like this:

Set the adjustable top by screwdriver to 1/3 path or 45°. Like on photo. If you set it too much on left, you will get ERROR 91 LOW SALT. If you set it too much on right, you will get ERROR 92 HIGH SALT. This position worked in my case, but if you will get ERROR, just move it a bit in correct direction.

Put all wires back withou any change. See little blue adjustable FAKE SALT LEVEL unit installed ;-)

Close the cover, connect it back to pool hoses and simply run it. All functions remains the same and you will never get LOW or HIGH salt error again. Simply errors 91 and 92 are gone forever.

Keep in mind, that you set the salt level manually, that mean the unit is not measuring it. So you have to do it yourself periodically! The unit will never warn you! Also, you have to check the cell. There is no automatic control anymore.

I am very happy with this fix. Buy me a beer and enjoy error free salt water system :-)

Is your circuit board different? Well, the basic idea is to trace line from shunt to control unit. Shunt is U shaped thick wire on the board. Trace the line. It will probably lead to 8 pin integrated circuit, might be labeled as UC358. Output from this circuit will go to the main processing unit. You need to cut this trace and connect resistor between + and GND and the wiper to the processing unit.