Autopilot "Check Flow" Error

Jan 27, 2013
16
Richmond, Texas
Hi! I’m having some problems with my Autopilot (the unit is almost 6 years old). It started last summer. I kept getting a “Check Flow - Purifier Off” message. I researched several similar threads on here and tried everything I could to get it to work. So I gave it up on, put it in “purifier mode” and let it be. Last week, I went back out and thought I would try again. Put it in “total control” mode and it worked…but only for a day or so. My suspicion is that it’s the main board, but I wanted to get some other opinions or find out what else I can try before spending the money on a new board or unit.

Here is what I have tried already:
- cleaned skimmers, pump basket, DE filter and the manifold screen
- salt level is good, as well as PH, etc.
- plenty of water flow
- salt cell is clean
- checked & cleaned tri-flow sensor (actually my first suspicion was the tri-sensor and/or cord, so I bought a new tri-sensor & cord but that didn’t fix my problem)
- checked the bypass spring valve for debris
- I actually purchased a new interface board (part #838) last year, thinking that was the problem, but that didn’t fix my problem either
- visually inspected the fuses on the main board

One other thing to point out – I’ve noticed lately when I have the system in “purifier mode,” I will set it to a certain percentage (for example, 65%) and when I go out to check it a couple of days later, the display shows a totally different percentage. So it’s been acting kinda screwy.

Anyway, please let me know if there’s anything else I may be able to try or if I just need to break down and buy a new one. Thank you!
 
Welcome to TFP!

The percentage is expected to change with temperature, so a changing percentage doesn't really mean anything. It is possible for the percentage to change "too much" but that is difficult to distinguish from working correctly without a lot more information.

It is certainly possible for the main board to go bad in a way that causes that error message, but it is quite unlikely. Have you checked the flow sensor on the chemistry controller? Both flow sensors (tri-sensor and chemistry controller) will give that same error message if you are in either total control or PH control modes.
 
Update - I opened up the chemistry controller. The ORP, PH and flow sensors appear to be ok. I did take them out and check for debris and the float on the flow sensor does appear to be lifting with no problem. However, I did notice that the plastic housing (I believe it's called the injection flow cell) was cracked around one of the sensors, which was causing some pretty major air bubbles. So I have a feeling that is causing my problem. I ordered a new one and it should be here sometimes this week.
 
Darn...I spoke too soon! Now I'm getting the same "check flow at sensors" error again. I did notice that when I close the inlet valve to the flow cell (the one that turns the flow sensor on/off) and then turn it back on, the error goes away. But then it only works for an hour or so and I get the error message again. Any clue as what I can try next? Could it possibly be a bad flow sensor?
 
You can also program the unit to ignore the flow sensor. In the installer menu, Select System to TOTAL CONTROL. The next prompt ask, HAS FLOW SENSOR, set this to NO.

Usually when there doesn't appear to be enough flow through the flow cell, the manifold check valve may have some debris keeping it stuck opened slightly, a dirty cell, dirty manifold screen, or low flow through the system.
 
Poolsean said:
You can also program the unit to ignore the flow sensor. In the installer menu, Select System to TOTAL CONTROL. The next prompt ask, HAS FLOW SENSOR, set this to NO.

Usually when there doesn't appear to be enough flow through the flow cell, the manifold check valve may have some debris keeping it stuck opened slightly, a dirty cell, dirty manifold screen, or low flow through the system.


Thanks, I appreciate your response. Yeah, I currently have it running with no flow sensor. I will double check the manifold check valve, manifold screen and the cell.
 
Hello everyone! I am completely new to pools or to this website. However, I encountered the same problem that all of you are describing. I've just installed an indoor pool and it's been a bit more than a month since we started using it. I cleaned the filter myself following the instructions and since I put it all together, I keep getting the check flow message. My screen gets dirty super quick. I have to clean it 2-3 times a day on order for the error message to go away. Before I touched the filter, I haven't had any error messages and haven't cleaned the screen even once before. Please let me know what I can do to get rid of this message. Thanks!
 

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