Fleck 5600SXT flow indicator issue. Possibly RO system issue

[Aaron Blanco]

Hello.

I have used a Fleck 5600SXT (48k) in conjunction with an RO system and RO water reservoir for about 2.5 years in one of my coffee shops for water we use for coffee brewing. Cold water in our shop is treated (softened then RO) and hot water is city tap; and all our brewing equipment is fed from the cold line.

Recently our treated water pressure dropped to virtually zero (tap/hot remained the same). My brine tank water on my 5600SXT was very high and seemingly no regeneration or any activity was taking place. At first I cleaned out all salt from the brine tank and emptied it, thinking it might be a sludge/bridge issue, then re-added salt and did a regen. No change.

Next I purchased and installed a brand new 5600SXT system and installed it in place of the old system but I can still only get minimal pressure with the treated water. I have checked the bladder pressure on the RO reservoir and found it was only at like 1-2 psi; and boosted it to ~45psi from (the recommended minimum) with no change. The next morning I was down to ~43 psi, but this might have just been within the margin of error with my psi gauge.

Since installing the new system, the water level in the brine tank has remained the same (low/normal level). I have noticed the flow indicator icon (looks like a water drop) blinks anywhere from 10-20x every other minute or so then stops for a minute or so before doing it again. I can see that the gallons number indicating next regeneration goes down maybe a gallon or two every half an hour or so (I haven't measured how quickly gallons are counting down).

I have not tried to put this new system in bypass to see if the problem persists with a slow gallons countdown and intermittent water drop blinking because my coffee equipment relies on softened water or else it will calcify quickly in our local hard water; so I don't want to leave it on bypass for very long.

I did observe the discharge water tube seemed to drip continuously into the drain at perhaps a drop every other second. I can enter the shop in the morning after no water use all night and only get about 10-15 seconds of treated water pressure before it slows/stops. None of my equipment that requires pressure from the treated RO reservoir currently can be used because I don't have enough pressure.

My hypotheses are that either the RO reservoir bladder needs more than 45 psi (tank says 45-100 psi operational pressure). It's also possible the the Auto Shut Off valve on the RO system itself is not working and that's causing it to constantly drip from the waste line out? I have essentially ruled out the Fleck 5600 as the problem, since it's brand new. But maybe the flashing droplet is indicating a problem with the RO system?

Tomorrow I will add more psi to the RO tank and see if that helps. I have a brand new back up RO system I might install as well. At this point I'm just trying to troubleshoot down the line and feel like the Fleck part of the system is basically okay. I also have a new RO tank en route in case the bladder is no longer good.

I did very little programming in the setup of the new system. I believe I only changed water hardness level up a few points. All else was left alone.

Any thoughts on this would be much appreciated.

 

[Water Pro]

Hello.

I have used a Fleck 5600SXT (48k) in conjunction with an RO system and RO water reservoir for about 2.5 years in one of my coffee shops for water we use for coffee brewing. Cold water in our shop is treated (softened then RO) and hot water is city tap; and all our brewing equipment is fed from the cold line.

Recently our treated water pressure dropped to virtually zero (tap/hot remained the same). My brine tank water on my 5600SXT was very high and seemingly no regeneration or any activity was taking place. At first I cleaned out all salt from the brine tank and emptied it, thinking it might be a sludge/bridge issue, then re-added salt and did a regen. No change.

Next I purchased and installed a brand new 5600SXT system and installed it in place of the old system but I can still only get minimal pressure with the treated water. I have checked the bladder pressure on the RO reservoir and found it was only at like 1-2 psi; and boosted it to ~45psi from (the recommended minimum) with no change. The next morning I was down to ~43 psi, but this might have just been within the margin of error with my psi gauge.

Since installing the new system, the water level in the brine tank has remained the same (low/normal level). I have noticed the flow indicator icon (looks like a water drop) blinks anywhere from 10-20x every other minute or so then stops for a minute or so before doing it again. I can see that the gallons number indicating next regeneration goes down maybe a gallon or two every half an hour or so (I haven't measured how quickly gallons are counting down).

I have not tried to put this new system in bypass to see if the problem persists with a slow gallons countdown and intermittent water drop blinking because my coffee equipment relies on softened water or else it will calcify quickly in our local hard water; so I don't want to leave it on bypass for very long.

I did observe the discharge water tube seemed to drip continuously into the drain at perhaps a drop every other second. I can enter the shop in the morning after no water use all night and only get about 10-15 seconds of treated water pressure before it slows/stops. None of my equipment that requires pressure from the treated RO reservoir currently can be used because I don't have enough pressure.

My hypotheses are that either the RO reservoir bladder needs more than 45 psi (tank says 45-100 psi operational pressure). It's also possible the the Auto Shut Off valve on the RO system itself is not working and that's causing it to constantly drip from the waste line out? I have essentially ruled out the Fleck 5600 as the problem, since it's brand new. But maybe the flashing droplet is indicating a problem with the RO system?

Tomorrow I will add more psi to the RO tank and see if that helps. I have a brand new back up RO system I might install as well. At this point I'm just trying to troubleshoot down the line and feel like the Fleck part of the system is basically okay. I also have a new RO tank en route in case the bladder is no longer good.

I did very little programming in the setup of the new system. I believe I only changed water hardness level up a few points. All else was left alone.

Any thoughts on this would be much appreciated.

the RO storage tank should have around 6 psi (no more than 8 psi). the more air in the bladder, the less room for water. Try bypassing the softener and see if your main faucet pressure returns. If you provide more information, such as how much water you use daily and iron, hardness and tds raw measurements, somebody here may be able to help with the SXT programming.

 

[Sponsor]

 

[Reach4]

At first I cleaned out all salt from the brine tank and emptied it, thinking it might be a sludge/bridge issue, then re-added salt and did a regen.

Cleaning the injector (both pieces) and the injector screen might have fixed that, but maybe not.

I did observe the discharge water tube seemed to drip continuously into the drain at perhaps a drop every other second.

Are you referring to the drain line from the softener or RO unit?

Recently our treated water pressure dropped to virtually zero

You are referring to the RO output pressure, I think, and that is your symptom. I don't have RO, but I would think one of the filters for the RO is clogged and needs replacing. The membrane I would suspect and maybe others.

Also, with your high pressure output RO system, I expect you have an electric pressure pump in the RO system that may have failed. I don't know how you troubleshoot that. I am predicting that the backup RO fixes it, and maybe then rebuild the old RO at leisure.

I would not think a drop every other second out of the RO would be sensed by the softener turbine, or do you have a paddlewheel? Maybe put a container under the RO drain, if that is flexible, to measure the amount coming out of the RO drain.

I don't think adjusting your air precharge is going to fix this.

Not for this immediate problem, but you should get a Hach 5-B to test residual hardness from the softener.

There is a phantom water usage that can occur with water softeners feeding water heaters. Water gets heated, and expands, running water backwards through the softener. The turbine or paddlewheel counts movement in either direction. I don't know if your RO could be causing backflow, but a check valve on the output of the softener stops that. I am not seeing how this happens in your system, but if you determine there is phantom flow, you might consider adding a check valve.

 

[Aaron Blanco]

the RO storage tank should have around 6 psi (no more than 8 psi). the more air in the bladder, the less room for water. Try bypassing the softener and see if your main faucet pressure returns. If you provide more information, such as how much water you use daily and iron, hardness and tds raw measurements, somebody here may be able to help with the SXT programming.

I'll put it on bypass to test this out. I think you're right. We had the old Fleck on bypass for a half day last week as part of troubleshooting this down but 1) weren't sure we were seeing results because at the time we were chasing down ALL possibilities and probably didn't drill down enough on this one possibility; and 2) were wary of hard water in our equipment, as our city tap here can touch 275-300ppm as our main water source here is an underground aquifer with high lime and calcium. One question about the 6-8psi is whether this is the range for an RO system with an electric pump, which my RO system does NOT have. My assumption is that without a pump I need higher tank psi, even at the expense of having less stored water (I have a 20 gallon RO tank). Is that a bad psi/pump assumption? Thanks!

 

[Aaron Blanco]

Cleaning the injector (both pieces) and the injector screen might have fixed that, but maybe not.


Are you referring to the drain line from the softener or RO unit?

You are referring to the RO output pressure, I think, and that is your symptom. I don't have RO, but I would think one of the filters for the RO is clogged and needs replacing. The membrane I would suspect and maybe others.

Also, with your high pressure output RO system, I expect you have an electric pressure pump in the RO system that may have failed. I don't know how you troubleshoot that. I am predicting that the backup RO fixes it, and maybe then rebuild the old RO at leisure.

I would not think a drop every other second out of the RO would be sensed by the softener turbine, or do you have a paddlewheel? Maybe put a container under the RO drain, if that is flexible, to measure the amount coming out of the RO drain.

I don't think adjusting your air precharge is going to fix this.

Not for this immediate problem, but you should get a Hach 5-B to test residual hardness from the softener.

There is a phantom water usage that can occur with water softeners feeding water heaters. Water gets heated, and expands, running water backwards through the softener. The turbine or paddlewheel counts movement in either direction. I don't know if your RO could be causing backflow, but a check valve on the output of the softener stops that. I am not seeing how this happens in your system, but if you determine there is phantom flow, you might consider adding a check valve.

Yes, referring to the RO discharge line (on some systems with colored pex tubes it's black, which this one is as well). I've never tried to observe discharge flow rate from an RO system, so seeing that current FR I mentioned earlier might just be normal. Just wanted to give as much initial info as possible. I have plenty of test kits for total hardness, iron, a TDS meter, etc., as it is important for our operations to soften then RO down to essentially zero ppm then remineralize post carbon with a calcium, magnesium and sodium (sodium acts as a "buffer" for calcium and magnesium so that each is more effective at extracting solubles in coffee) filter to a total hardness of 100-125.

I don't even know how to determine a phantom flow to a heater, etc., but a check valve in any event sounds like a fine idea.

Thanks!

 

[Aaron Blanco]

Cleaning the injector (both pieces) and the injector screen might have fixed that, but maybe not.


Are you referring to the drain line from the softener or RO unit?

You are referring to the RO output pressure, I think, and that is your symptom. I don't have RO, but I would think one of the filters for the RO is clogged and needs replacing. The membrane I would suspect and maybe others.

Also, with your high pressure output RO system, I expect you have an electric pressure pump in the RO system that may have failed. I don't know how you troubleshoot that. I am predicting that the backup RO fixes it, and maybe then rebuild the old RO at leisure.

I would not think a drop every other second out of the RO would be sensed by the softener turbine, or do you have a paddlewheel? Maybe put a container under the RO drain, if that is flexible, to measure the amount coming out of the RO drain.

I don't think adjusting your air precharge is going to fix this.

Not for this immediate problem, but you should get a Hach 5-B to test residual hardness from the softener.

There is a phantom water usage that can occur with water softeners feeding water heaters. Water gets heated, and expands, running water backwards through the softener. The turbine or paddlewheel counts movement in either direction. I don't know if your RO could be causing backflow, but a check valve on the output of the softener stops that. I am not seeing how this happens in your system, but if you determine there is phantom flow, you might consider adding a check valve.

Check valve would go AFTER treated water has exited the final RO filter and before going out to the rest of the "house"?

 

[Bannerman]

The softener and RO are two seperate systems. You will need to first diagnose if the flow problem is caused by the softener, which is simplified if it is supplying other faucets in addition to supplying the RO system. You said the softener is feeding the cold water plumbing, but it remains unclear if the RO system is the only device/faucet/item that is being supplied softened water.

If the softener is confirmed not to be the cause of the flow issue, then the RO unit will become the focus.

The Fleck 5600 valve maybe utilized for a variety of softener capacities and so, will often not be correctly pre-configured for your specific capacity or application. Suggest posting the current settings, water hardness, the BLFC flow rate (stated on label located close to the brine tube connection), so we may offer appropriate programming advice. If you have an idea of soft water consumption, that will also be useful.

An RO feed will typically pass through at least 2 cartridge filters, 1st a sediment cartridge and the 2nd being activated carbon to remove chlorine and other contaminants the membrane cannot tolerate or otherwise remove. After the 1st carbon, water will flow through the ASV to the membrane, and the RO water exiting the membrane will flow to the storage tank. Water exiting the storage tank will typically flow through another carbon cartridge to further polish the water on its way to the RO faucet(s) and in your case, to your brew equipment.

Some of the water entering the membrane housing is utilized to rinse away rejected minerals and contaminants which will not pass through the membrane. The rinse water will flow continually to drain while the RO is producing RO water (aka: permeate). The flow rate to drain is controlled by a flow restrictor which is to be matched in relation to the capacity of the membrane.

RO production is controlled by the ASV. When the ASV senses the storage tank pressure has risen in percentage relation to the incoming supply pressure, then no further flow will be supplied to the membrane, thereby stopping RO production and also halting flow to drain. A standard ASV will stop flow once the water in storage has risen to approx 60% of the supply pressure. For example, if the supply pressure is 60 psi as it will be from many municipal supplies, then the maximum RO pressure will be ~36 psi which will become lower as water is drawn faster from the storage tank than is supplied by the membranne.

Increasing the storage tank pre-charge pressure will not increase the pressure to the RO faucet/brew equipment, but will only reduce the quantity of RO water the tank can store.

As already mentioned, the tank precharge will be typically 6-8 psi which will ensure the tank will continue to supply sufficient flow velocity even when the storage tank contains little remaining water.

The replacement requirement for RO filter cartridges is typically 6 months, and 3-5 years for membrane replacement for a residential application. Since you are likely using significantly more RO water than most families, the filter and membrane replacement will need to be more frequest so, recommend replacing all once verified the softener is not the cause.

To increase the pressure of the RO water, either an electric booster pump may be utilized to boost the supply pressure to the RO unit, thereby increasing the pressure of RO to 60% of the boosted supply pressure.

Alternately, the unit maybe retrofitted with a Permeate pump which is a non electric pump that is 'powered' by the water flowing to drain.. A PP will eliminate back pressure on the membrane, allowing it to operate more efficiently, thereby increasing it's daily production capacity to supply higher quality water than presently obtained. When utilizing a PP, the ASV is often removed or preferably replaced with a higher pressure version that will allow storage pressure to rise to ~90% of supply pressure before RO production is shut down. A PP maybe combined with an electric supply booster pump to further increase the final maximum RO pressure.

The animation and link below shows the function of a PP.

https://www.permeate-pump.com/ERP1000_anim02.htm

https://www.permeate-pump.com/ERP1000ben.htm

 

[Reach4]

One question about the 6-8psi is whether this is the range for an RO system with an electric pump, which my RO system does NOT have. My assumption is that without a pump I need higher tank psi, even at the expense of having less stored water (I have a 20 gallon RO tank). Is that a bad psi/pump assumption?

I think that is a bad assumption.

I am not sure what your air precharge should be. Clearly at 40 psi the air precharge is too high to let water fill the tank. Will dropping the pressure down to 6 psi make the system useful? I suspect yes. It will let water accumulate if the RO unit can produce water at higher pressures. As long as water at 6 psi is useful, yes, 6 psi would be a good precharge probably. Without a pump, I doubt that you get 80 psi RO water.

 

[Aaron Blanco]

UPDATE: RO system swapped out (new one for old one). Tank psi tuned down to 8psi. System working flawlessly. RO membrane was the issue. It got worn out much faster than it was scheduled to. Thanks everyone, for helping me troubleshoot the issues aloud and for your great feedback. Now the old softener and RO is backup/parts.

I'm heading out of town for a week but do plan to ask help programming this softener to optimize it. Thanks again!