Fleck 9100 SXT not drawing brine, cam stops in wrong spot

[Nakorkren]

I recently bought a house with a Fleck 9100 SXT, twin 24k grain tanks. The unit has not consumed any salt in since we moved in about a year ago, and I have finally gotten around to looking into it (newborn and toddler consume my free time).

The drain line runs just fine, I cleaned the two pieces of the injector as well as the screen, and replaced the brine line (which had a nick in it), but the system still does not draw brine. I also noticed that the brine fill is extremely short, just a few seconds long, even though the setting in the controller for BF is set to 7, which I assume is minutes.

I noticed something quite odd. During backwash, the cams are in a specific position. The digital controller then advances to the 60 minute brine draw and rinse, but cams do not advance at all. Later in the cycle, when the cams do advance through the rest of the rotation, there IS suction on the brine line for a few seconds, and then it stops after the cams get past the small land that triggers the brine valve. I assume the system should be advancing onto that small land and then dwelling there for the 60 minute brine draw and rinse phase, but instead it sits BEFORE that land for the full 60 minutes. Any thoughts on what's going on?

Programming settings are below for reference:

DF: GAL
VT:dF1b
CT:F1
NT:2
T5:u2
C:24
H:20
RS:SF
SF: 10
DO: 11
RT: 2
BW: 10
BD: 60
RR:10
BF:7
FM:t0.7

 

[Bannerman]

I suspect it is time to rebuild the valve with new seals, spacers, brine valve and possibly pistons. Those are consumable items that require periodic replacement. Soft items such as seals, O-rings etc, will degrade more rapidly when there is chlorine in the water which is typically added to municipally supplied water as I suspect you use.

What are the tank dimensions?

Although you said it has twin 24K tanks which will most commonly refer to 0.75 ft3 resin contained within 8" diameter tanks, that seems to be a small system for a twin. Also, a 24K grains Capacity setting should not be programmed for 0.75 ft3 resin.

 

[Sponsor]

 

[BkE]

It might be a microswitch problem..

 

[Nakorkren]

We are on municipal water, so it does likely have some chlorine in it, and since the system is 12 years old, it probably is time to replace the various consumable items. I assume there are kits available to do so... anyone have a recommended vendor?

Each tank is 8" diameter by 44" tall, brine tank is 18" diameter by 33" tall. The paperwork the previous owner left me says 24k grain capacity per tank.

I don't understand your last comment that "a 24K grains Capacity setting should not be programmed for 0.75 ft3 resin." Is that how my system is currently set up? What parameter in the programming list controls that?

I don't understand the connection between the seals and such being old and the issue I'm having, since the system is capable of pulling suction, it just isn't doing so when it should be. Like BkE mentioned, I was wondering if it might be an issue with one of the switches that rides on the cams, but I don't yet understand what those cams and switches do in the system, so obviously I'm just guessing.

Bannerman, from your other posts you seem to be extremely knowledgeable about these systems! Would one of those switches going bad cause this kind of issue? Is there any other troubleshooting you recommend?

 

[Bannerman]

I attempted to locate a video showing the rebuild procedure for 9100SXT. The closest I could find is one for 9100TS which includes 2 additional sensors your unit will not be equipped with, and the TS model is configured for up-flow brining while yours will be downflow.

The other parts of the valve is very similar to yours. While the speciality tools can make the job quicker, particularly if you rebuild valves for a living, for a one time rebuild, you should be able to pull out and replace seals and spacers with your fingers or basic common tools.

When the soft items such as seals become worn, torn or chlorine damaged, being a mechanical device driven by 1 motor, the piston will no longer move easily and can bind and slow down or jam the motor which can cause other parts to not operate as intended.

To regenerate all 24,000 grains capacity will require 15 lbs salt each regeneration which would be extremely inefficient. Hardness Reduction Efficiency = 24,000 / 15 = 1,600 gr/lb

Regenerating 24K will also be unrealistic as some resin granules will be undersized or fractured during manufacturing so those damaged granules will be flushed to drain during the initial backwash cycles, and as the resin becomes worn over time. Each of your tanks will no longer be capable of removing all 24K grains hardness but some lower amount which is a common situation for all softeners.

To increase efficiency and to reduce hardness leakage, the Capacity setting should be reduced which will allow the amount of salt required to be also reduced.

After rebuilding the valve, recommended Capacity setting to be programmed will be 18,000 grains (C = 18) which will require only 6 lbs salt each cycle. (Hardness Reduction Efficiency: 18,000 / 6 = 3,000 gr/lb )

Look for a label nearby to the brine line connection which will indicate the BLFC (brine line flow control) flow rate. That flow rate (ex: 0.25 or 0.5 GPM) X Brine Fill minutes = the quantity of water to enter the brine tank. Each gallon will dissolve 3 lbs salt so for 6 lbs, only 2-gallons will be needed.

 

[Nakorkren]

I disconnected each of the two normally closed (NC) switches in turn and confirmed that they're still functional. While I had the center one (which rides on the Hcam) disconnected, the cams/gears started advancing, despite not having initiated a manual regen. I believe the Hcam is the cam responsible for signalling to the digital controller that the cycle either has started or ended, as it has only a single notch in it.

After reconnecting the switches and letting the system get back to Standby, I ran another manual regen just so I could take some video and get pictures in the various phases. Much to my surprise, the system now DOES advance after backwash and is now pulling in brine during the brine draw and rinse phase. I am always suspicious of "fixes" that you don't understand, so I don't know if it is truly "fixed", but it seems to be working correctly now. I'm letting it run through the 60m brine draw cycle and will check the brine fill as well.

I will reprogram it with your recommended parameters above and keep an eye on it in the mean time while I wait for replacement seals/orings to arrive. Thanks for your help!

 

[Bannerman]

Perhaps there was some corrosion so pulling off and reconnecting the terminals restored the electrical connection.

Because the resin's total 24 K grains capacity has been exhausted, recommend now regenerating the resin's total capacity in each tank. As that will require 15 lbs salt for each, you could add additional water appropriate to dissolve 15 lbs using a bucket, wait 1-1.5 hours to allow additional salt to dissolve then perform a manual regen cycle. This will need to be performed 2X so both tanks will be fully regenerated.

Will need to know the BLFC flow rate to determine the amount of water currently within the brine tank so as to calculate how much additional will be needed.

 

[Nakorkren]

It's hard to tell because the marker was worn away, but I believe the BLFC says 1.5.

 

[Bannerman]

but I believe the BLFC says 1.5.

That will be 1.5 lbs/min which is a 0.5 GPM BLFC.

For 6 lbs salt, the BF setting will then be 4-minutes.

The current BF=7 minutes will cause 3.5 gallons to enter the brine tank. 3.5 gallons X 3 lbs = 10.5 lbs salt which is insufficient to regenerate 24K grains Capacity even while the valve was working properly.

As there is currently 3.5 gallons in the brine tank, add a further 1.5 gallons before performing the 1st manual regeneration specified above. If you change the BF setting before performing the 1st cycle, only 2-gallons will enter the brine tank during BF so you will need to add a further 3 gallons before performing the 2nd manual cycle to restore the 2nd resin tank.

 

[Water Pro]

It might be a microswitch problem..

good catch without recognizing the microswitch signal, it will advance past the cycle.

 

[ditttohead]

A couple of not so very common issues with the 9100SXT. Rare but it does occur. Run the system through a regeneration and carefully watch the microswitch cam. If the valve is binding we have seen where the cam will flex and send a false signal to the electronic board by momentarily causing the switch to engage or disengage.

 

[Water Pro]

A couple of not so very common issues with the 9100SXT. Rare but it does occur. Run the system through a regeneration and carefully watch the microswitch cam. If the valve is binding we have seen where the cam will flex and send a false signal to the electronic board by momentarily causing the switch to engage or disengage.

I've experienced that with a "c" unit. I realized it wasn't the actual cam flexing, but the motors cam shaft had play in it.