Reverse Osmosis Troubleshooting Guide

Find RO Systems

Find RO Replacement Filters

Find RO Replacement Parts

If your reverse osmosis water filtration system does not seem to be working correctly, here we provide a list of possible issues you may be experiencing, and their potential solutions. Please understand that the solutions offered are given as a general guideline, and we strongly recommend that you consult your specific RO systems’ owner’s manual and/or local water treatment specialist.

Symptoms

 
 

Symptoms

Probable Cause

Solution

NO WATER

1. Tank improperly pressurized

2. Over pressurized tank

3. Water supply turned off

4. Low water pressure (40 psi min)

5. Pre-filter clogged

6. RO membrane damaged or clogged

7. Product line crimped

8. Post-filter clogged

9. Ball valve on RO tank closed

10. Check valve/restrictor valve clogged 

Set tank pressure at 5-7 psi when empty

Check RO storage tank optimum pressure 5-7 psi when empty

Call for assistance – may 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

Call for assistance

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

Replace – If TDS rejection is below 80%

Replace

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

Sanitize system

CLOUDY ICE CUBES OR MILKY COLORED WATER

1. Bad Membrane

2. Water supply

3. System or filters are new 

Call ESP 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 – call ESP for assistance

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

ICE MAKER NOT WORKING

1. Shut off valve to ice maker not open.

2. Ice maker in handle in refrigerator in off position

3. No water in R.O unit storage tank 

Open shut of valve

Place in on position

Check RO unit

NO WATER DISPENSED FROM REFRIGERATOR DOOR

1. Reservoir in refrigerator is not full

Hold down refrigerator water dispensing handle for 2-3 minutes to draw water through system. If no water is produced check RO unit for water flow.