H2O RO Low Feed Pump Pressure

[Amber Gold]

I have an H2O Econox 600 RO machine they're shutting off because of low pressure

My before prefilter pressure is about 40psi, and the after prefilter pressure is only 18 psi. In the off-season, my after filter pressure gauge maxed out, so I don't know what it used be, but I know it's not 18 PSI. Because of the low pressure, it will not stay running during my rinse cycle. I have run it with, and without, a filter inside the housing and still no go.

Is there an issue in the feed pump because it's not building pressure? Can this be fixed?

Can the pressure switch setting be changed, so I can get through the season? This year, I was planning on bringing the RO back to H2O anyways to have them go through it, but I need to do something to get me through the end of the season.

Thanks for your help.

[Brian]

There might be somthing in the feed pump turbine that is not letting it build pressure. I had a mouse build a nest in mine years ago, he got in through the drain that i left open in the off season.

[wiam]

My cdl has a stainless Goulds feed pump. The plastic diffuser broke somehow a couple years ago. That gave me low pressure issues. Replaced diffuser and good as new.

[Amber Gold]

Do I take the pump cover off to inspect? I can try that tomorrow.

Thanks guys

[Amber Gold]

Quick update.

From the feed pump, I removed the drain plug and discharge pipe, so I could see inside the pump head. All looked good as far as I could tell.

What I don't understand is why there's 40psi before filter and 18 psi after filter...why the 20+psi pressure drop when there isn't a filter in the housing...that doesn't make sense.

From what I can see, there isn't a clog in the piping: from perm. tank to RO (all 1.5" PVC supply line) and between the pressure sensing points (some of the piping is clear).

I'm working with H2O to lower the low pressure off setting to at least get me through the season.

[maple flats]

Do you change the filter daily? You should!

[Bricklayer]

There is definitely a plug somewhere. Is there a line going to the pressure gauge and the low pressure switch from the filter housing or anywhere after the filter housing ?
I had problems with my gauges last year and it ended up being a little piece of scale or minute piece of something that got by the filter. It got stuck in the orfice of the switch. I had to use a sewing needle and just poke it and rinse it out.

[Amber Gold]

I do change the filter regularly.

I checked the lines going to the pressure gauge and pressure switch, and they're all clear.

For a temp fix, since the before filter pressure gauge is reading 40+ psi, I sent that line to the pressure switch, and things are back up and running.

I concentrated last night, and the after filter gauge was reading 50-60 psi, so the low pressure issue is only on a rinse/wash cycle, and it doesn't matter what tank a pull from: sap, permeate/wash tanks, they all have low pressure. I'm not sure what's the difference in how the RO operates between wash/concentrate modes, but that seems to be the issue.

The machine is 10 years old, so this off-season I was going to bring the RO to H2O to have them go through it...it sounds like a great idea now.
I'm up and running now, and the help is greatly appreciated. Thanks

[Polaris1]

Is it happening only on the wash rinse cycle? On my Econox 600 when I wash or rinse I set my after filter pressure to 30 psi by the V3 valve. Thats according to H20 directions for wash rinse cycle.

[Mavitec]

Hello Amber Gold, personnally I would be carefull with changing the pressure setting on the feed pump swith or changing the location of the pressure switch because It seem like you have obstruction in your filter housing and if the pressure to the high pressure pump is low you will ruin your high pressure pump. I have buy a used Lapierre Turbo 250 this season and the owner told me he had just installed a new high pressure pump. I changed the bearing on all the other pumps (as maintenance before the season begins) and foundout that the feed pump impeller was full of wool & plastic parts. I beleive that the cause of the failure of the high pressure pump was from cavitation caused by the feed pump just barely pushing over 20 psi.

[Amber Gold]

Polaris1, I looked at my owners manual, and it says to put it on the rinse setting for rinse/wash cycles. It doesn't say anything about adjusting valves to build pressure. I do have the 2019 manual, and I see it says to put V3 in the middle between wash/conc. for a sugar push. For a perm. rinse, it says to turn V3 to rinse/wash mode. And for a wash cycle, it says to adjust V3 to maintain 35psi in a rinse/wash cycle. These are new and isn't in my original manual. I don't understand what turning V3 does in regards to flow routes in the RO system, but I wonder why the change in settings from original manual to current, and why a rinse setting is different than a wash setting.

Mavitec, thank you for that and cavitation was a concern. I did confirm that maintaining 10psi is OK for the high pressure pump. Also, the pumps sound fine, and I do not hear it cavitating. With my current setup, the pressure switch is reading before prefilter pressure and the pressure guage is reading after prefilter pressure, so I'm kinda monitoring pressures on both sides.

I did look inside the feed pump housing with a flashlight, and it looks OK inside...no crud buildup and nothing broken.

[WMF]

If you don't have a coarse screen type filter on the inlet to the feed pump you probably have debris wedged in the impeller. Junk gets caught in closed impellers because they narrow near the outer diameter and you can't see it from the pump inlet. Only way to clean is to remove pump housing which is usually easy and usually you can re-use the oring. What brand pump is it?
The prior owner of my ro used a mop to clean tanks and the pump impeller was full of blue mop strands and several small stones.

[Amber Gold]

Good thought. The unit does have a coarse screen filter before the filter pump.

Pumps don't like stones...

[eagle lake sugar]

Did you figure out your problem? I haven't been on this site for a while, so didn't see your post. On the single membrane econox 600 you can't put the lever all the way to the rinse position, it will shut down as yours is. If that's your issue, just run it half way between the concentrate and rinse positions and it will work fine.

[Amber Gold]

Eagle Lake, that's what others have said too about leaving it partially open. What threw me off this year is I've never had to do that before...I've always had the valve all the way to the rinse position.

[eagle lake sugar]

Eagle Lake, that's what others have said too about leaving it partially open. What threw me off this year is I've never had to do that before...I've always had the valve all the way to the rinse position.

That is odd. My 600 would always shut down unless I left the valve partially in the concentrate position. I have a 1200 now and you can put that in the full rinse position no problem. BTW I love the 1200, I concentrate at about 900-1000 gph at 16% all day long and it never slows down a bit.