Replacing my SWG


New member
Jul 2, 2010
I just purchased a home with a salt water pool that is 2 years old and 22,00 gallons. It has an Autopilot SWG unit installed that has been giving me trouble, and basis some notes left by the previous owners, gave them trouble too. The flow switch just went out (again - second one in 2 years, and the salt readings and temperature are all over the map).

Since the cell is 2+ years old, and it is going to cost me about $250.00 for the switch and a service call, by the time I am done, my cost will be about $350.00 on a two year old unreliable unit.

My question is....does anyone have a view on which unit to install (and who has the best warranty?). My pool company wants to sell me a Hayward Aqua-Rite unit.

Many Thanks,



TFP Expert
LifeTime Supporter
Apr 4, 2009
Welcome to TFP :wave: Before you dump the autopilot...they are actually pretty nice high end units and the cell should be able to last much longer than 2 years.

1st step would be to get a good test kit and some salt test strips. is popular here and the owner actually owns TFP as well. 2nd Read pool school and ensure your chem levels are in line with the recommended SWG balance parameters
3rd, check to make sure you are actually getting good flow from your returns, does your filter need to be cleaned? Also, it would hurt taking the cell out and see if that needs a cleaning.

Post a full set of results as soon as you can and perhaps we can save you a few $'s.

This is what we'll need to help you out:



New member
Jul 2, 2010
I had the water tested a few days ago by a pool store. Here are the results:

FC - Free Chlorine - 3.0
CC - Combined Chlorine - Don't have
pH - 7.8
TA - Total Alkalinity - 110
CH - Calcium Hardness -260
CYA - Cyanuric Acid (stabilizer) - 90 ( just added 8 lbs)
Salt - 2900 ppm

Copper - 0
Iron - 0
Phosphates - 100 (I just added some remover)

As you mentioned, I took the cell out last week, and cleaned it with 4:1 acid. It had some deposits, but not all that much. Also, I do not believe there is flow restriction or dirty filter. The pressure reading on the filter top is about 22 psi, and has been steady for the last few weeks.

Do you know why the Tri sensor would go out twice in 2 years? Which replacement unit would you buy?


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
It is very unusual to have that much trouble with the tri-sensor. Flow switches do fail with any brand of SWG, but not normally anywhere near that quickly. Your problem sounds like it could be a lose/bad connection at the power supply/control unit end of the tri-sensor cable.

Also, the tri-sensor cable should not be tightly coiled anywhere along it's length.


TFP Expert
Apr 15, 2007
Ft Lauderdale, Florida
Flyboy, PM me your address so I can pull up the previous service call reports to see what my service center diagnosed. Sure helps to have both sides of the story, rather than notes written by the previous owner. Were there any service report copies left behind?