ATK overfilling after reset

[nullbreached]

Although I’m generally happy with the performnce, I’ve been experiencing inconsistent behavior from the FMM/ATK. In situations when the freshwater reservoir reaches empty because I didn’t fill it in time the unit shuts off automatically as it should or more frequently, I turn it off manually so the pump runs dry as briefly as possible.

After filling the reservoir and setting the ATK to ON then AUTO things seem to work fine if the short term. But occasionally, especially after an overnight sometimes the unit will overfill, filling quite a bit past the second sensor. This is confirmed by the checking the dashboard, with both sensor positions closed—so the sensors are functioning.

I’m not sure where to start. It’s a 15 gallon sump.

Here’s my existing code:

Fallback OFF
Set OFF
If Swx10_1 OPEN Then ON
If Swx10_2 CLOSED Then OFF
If FeedB 000 Then OFF
When On > 004:00 Then OFF
Defer 000:10 Then ON
Defer 000:04 Then OFF
Min Time 060:00 Then OFF

[rkpetersen]

Does your setup require a siphon break? Is this occurring when the reservoir is nearly full? If so, you may be getting a brief siphon situation despite the presence of the break. The break's function can be inconsistent until the water level is at least 1 cm below the side hole.

[nullbreached]

Does your setup require a siphon break? Is this occurring when the reservoir is nearly full? If so, you may be getting a brief siphon situation despite the presence of the break. The break's function can be inconsistent until the water level is at least 1 cm below the side hole.

That's a good suggestion. Coincidentally, yesterday, I was unable to fill the reservoir to capacity so that seems unlikely—though theoretically possible since the level would probably have been slightly higher than the sump section. Also, if it were to happen at maximum reservoir capacity it would probably have resulted in more severe problem. The last sump section overfills but not to that degree.

I guess I can setup a scenario to test for it regardless.

[zombie]

That's a good suggestion. Coincidentally, yesterday, I was unable to fill the reservoir to capacity so that seems unlikely—though theoretically possible since the level would probably have been slightly higher than the sump section. Also, if it were to happen at maximum reservoir capacity it would probably have resulted in more severe problem. The last sump section overfills but not to that degree.

I guess I can setup a scenario to test for it regardless.

If the full water level in the reservoir is higher than the ATK low sensor, you need the siphon break. The problem didn't ball on out of control because the float switch limited the water level to its own setting in the event of a siphon.

You might be an engineer if...You have no life and can prove it mathematically.

[nullbreached]

Yep—I do have the siphon break installed.

If the full water level in the reservoir is higher than the ATK low sensor, you need the siphon break. The problem didn't ball on out of control because the float switch limited the water level to its own setting in the event of a siphon.

You might be an engineer if...You have no life and can prove it mathematically.