Reverse Osmosis Troubleshooting Guide


Probable Cause



1. Water supply turned off

2. Low water pressure (40 psi min)

3. Pre-filter clogged

4. RO membrane damaged or clogged

5. Product line crimped

6. Post-filter clogged

7. Ball valve on RO tank closed

10. Check valve/restrictor valve clogged


require pressure pump

Turn water supply on

Replace pre-filter

Replace membrane

Remove crimp in line

Remove post-filter

Open RO tank ball valve

Replace check valve/restrictor

SLOW FLOW THROUGH FAUCET 1. Pre-filter clogged

2. Post-filter clogged

3. Low air pressure in RO tank

4. Low incoming water pressure (min 40 psi)

5. Fouled RO membrane

6. System, filters, membrane new

Replace pre-filter

Replace post-filter

Raise pressure in RO storage tank to 5-7 psi

Replace RO membrane

Allow 4-6 hours for system to fill


LEAKING MEMBRANE HOUSING 1. Threaded end cap leaking

2. Cap or body of housing leaks

Lubricate o-ring with Dow 111 silicone sealant and retighten if leak continues replace with new lubricated o-ring.

Check for any cracks in membrane housing and/or housing cap – if cracked or damaged replace both cap and housing

LEAKING PRE or POST FILTER HOUSING 1. O-ring not seated properly or filter housing cap not screwed on tightly

2. Housing damaged

Is o-ring in groove. Check for damaged if found replace o-ring. If dirty clean, lubricate Dow 111 silicone sealant – retighten lid. Hand tighten only

If any detectable damage or cracks replace housing and lid

LEAKING FAUCET 1. Fitting Leaks

2. Leak at base of brass stem

3. Spigot drips

Tighten fitting – make sure tubing is pushed
into fitting /base of faucet stem

Replace faucet

May require installation of faucet repair kit

BAD TASTE or ODOR 1. Defective unit

2. Bad membrane

3. Exhausted filter (s)

4. Not enough water used

5. System needs sanitizing


Replace – If TDS rejection is below 80%


Drain system – do not allow water to remain unused more than 5 days

Sanitize system


2. Water supply

3. System or filters are new

 for information on TDS testing

High oxygen content –Tiny bubbles – will go away with use

Air in lines – will go away with use

NOISEY DRAIN OR FAUCET 1. Air gap faucet

2. Drain tube

A little noise is common with air gap faucets. Check your owners manual to be sure air gap is installed in proper location

Air in systems may take up to two weeks to purge air from system under normal use.

Check drain line from faucet runs down hill to drain saddle clamp. Loops, bends, dips or kinks can cause noise.

LEAKING FITTING 1. Fitting damaged or cracked

2. Tubing not pushed securely into fitting or threads not properly installed

Replace fitting

Check tubing installation & thread installation.

SYSTEM IS CONTINUALLY RUNNING 1. Automatic shut off valve not working

2. Low incoming water pressure

3. Low RO storage tank air pressure

4. Damaged or ruptured RO storage tank bladder.

5. Flow restrictor in drain line worn out.

6. Membrane incorrectly installed

Replace automatic shut off valve – be mindful of where the four lines are removed and reinstalled.

Increase water pressure – minimum required 40 psi –

Check air pressure in RO Storage tank – optimum 5-7 psi when empty

Replace RO storage tank

Replace the flow restrictor that matches membrane capacity

Check membrane installation instructions