[Sid123]

Hi,
Need some advice.
I have a pure freedom 4040 RO with a big booster pump. Over the last few months the pressure on the RO has dropped to 30psi from where it would normally sit at 40psi. I didn’t realise how big an impact this would have but my very expensive HF5 membrane has now bitten the dust after just 6 months!!. (Gutted)
Tonight I checked the tap PSI with a screw on gauge and it was 40psi!. Should I really be losing half my pressure through the RO system (it reads 20psi before turning the booster pump on and totalling 30psi).
Would this indicate my RO is furred up or somehow has an airlock?.

[chris turner]

Check the membrane is the right way round. The rubber seal should be closest to the opening.
A friend had his the wrong way round for a while and had similar results to yours.
Another thing to check is the tap. I routinely take my tap off and clean it as limescasle builds up and really affects the flow and pressure.
My tap pressure is same as yours 20 psi, with booster pump it goes up to 65 psi and my spectrum membrane produces nearly 200 litres an hour.
Also do you ever flush the membrane? And how often do you change the prefilters?

[Sid123]

Hi, thanks for your reply. Ok will check membrane tomorrow but I think the 4040 HF5 looks the same too and bottom?.
Re flush I do this once a week and change the pre filters every 3 months.
Also my tap pressure is actually 40psi! So my RO with the booster pump on is producing less pressure than at source

[Smudger]

what pressure should the pump be putting out?

are you pumping through the pre filters all just the membrane ?

I found that I would go through a membrane every nine months - I did some research and increased the feed pipes to 1" from
15 mm  - this has allowed the pump more water volume - the current membrane is now 18 months old and still producing 006 from the mid 300's

Darran

[Don Kee]

Forget your mains tap psi, what pressure are you getting after the “big booster pump”?

Unless I’ve read it wrong, you say your RO would normally sit at 40psi and your tap pressure is at 40psi; so what exactly is your booster pump doing?

[Sid123]

Thanks for both responses.
Regarding the diameter hoses i set it up with some high pressure hose I had left over. I don’t know the exact dimensions but it would be smaller internal dimensions to that of a normal hose pipe.
I could try swopping that out maybe.

So regarding the pressure.

Tap pressure is 40psi.
RO BEFORE booster pump used to be 30psi
RO with booster pump ON was 40psi

Now
RO BEFORE booster pump is 20psi
RO with booster pump ON is 30psi

Now 30psi just isn’t enough pressure to maintain the membrane. So it’s sniffed it in 6 months.

So this leads me to conclude it’s bay my equipment is defective. I don’t see how my RO can produce less pressure than what it’s started with. Surely if anything pressure should build?

[Smudger]

For a start your starving the system of water - esp now its summer as the water board will reduce pressure from their end

we really need to what pressure is coming from the pump

Darran

[Don Kee]

Regarding the diameter hoses i set it up with some high pressure hose I had left over. I don’t know the exact dimensions but it would be smaller internal dimensions to that of a normal hose pipe.
I could try swopping that out maybe.

Put some bigger diameter hose on, your 4040 will want a high water flow (as well as pressure) and you’re restricting it. Let the pump worry about the pressure.

So regarding the pressure.

Tap pressure is 40psi.
RO BEFORE booster pump used to be 30psi
RO with booster pump ON was 40psi

Now
RO BEFORE booster pump is 20psi
RO with booster pump ON is 30psi

Now 30psi just isn’t enough pressure to maintain the membrane. So it’s sniffed it in 6 months.

The pump when working is only raising the pressure up to 40psi (so raising by 10).
That’s awful.

For context, my mains pressure is 40psi, my booster is set to 80psi (I could have it higher but that pure/waste ratio seems to be my sweetspot).

So couple of things to try.
Your waste valve isn’t set correctly so
 close your gate valve a little and watch the pressure go up.

Or

Your booster pump knackered.

(Might also be worth checking your prefilters. If you’ve not changed them for a while they may be clogged up, restricting flow. Check the sediment fileter and see how “dirty” it is if you can’t remember when you last changed them.

[Sid123]

Hi,
Thanks will take off the hose and replace with garden hose to see if this improves things any.

Regarding other points have already checked both gate valves time and time again. Closing the waste valve a bit just reduces water pressure further. Tweaking the gate on the booster pump also results in a further dump of water pressure. So I have no adjustment “tools” on the setup that will make any difference.

Booster pump is most likely knackered, I sent a vid to pure freedom and they feel it’s probably had it. Oddly I think the pump deteriorated when the water pressure reduced, so the gradual reduction in water pressure has knackered both the membrane and the booster pump - potentially. Very expensive!
Another thing which £issues me off is that I’ve been buying these expensive HF5 membranes but in fact I have adequate tap pressure to accommodate a cheaper HF4!. So again it’s the fookin RO by the look of it which is costing me a fortune due to some issue!

[Sid123]

Just checked the diameter of the pirtek high pressure hose internal is the same as garden hose so absolutely no point on changing that!. I’m at a total loss.

[Smudger]

Change it to 1”  bore hose

But if the pump is duff then your wasting time/effort until replaced

[simon w]

Take each suspected problem part out of the system one at a time looking at the pressure until you find the culprit , I.E run without RO, then pre filters, then booster pump etc .

I have a heavy duty booster pump for sale if you find yours is beyond repair and you don't want to buy new. Bristol collected.