Troubleshoot Guide: Bad Taste or Bad Smell - RO-Pump

To determine what's causing the "funny" taste, please do the following for us:

  • Check the TDS (contaminant) level at different points along the system.
  • Do a taste test at these points to identify where the water begins to taste bad.
  • Test the "waste water" to "pure water" ratio.

(Test: waste ratio, test tds & taste at: Point D, T1, G)


Please do the test steps listed below. Use the TDS meter (water quality tester) to test your TAP and Filtered water. Please see the figure below for reference points.

Test #1: Waste Water Ratio

Purpose: The RO takes 4-5 gallons of waste water to make 1 gallon pure water. So the "Waste Ratio" should be 4:1 to 5:1. If wastewater is less than this ratio, the TDS will be high. Test waste ratio as follows:

  • Close the tank valve.
  • Remove the BLACK drain line from the drain saddle. Put line in a bucket to catch the wastewater.
  • Remove the Clear line from point T1 (Right hand side of the TSO). Pure water will flow out of the line in a small stream.
  • Fill up an 8 oz cup from this line ---> this is PURE water from the membrane.
  • Measure the amount of WASTE water the RO generated to make the 8oz pure water.
  • Are you getting about 4 - 5 cups of waste water for 1 cup of pure water?
  • Record the "waste ratio". Give us the number.

Test #2: Point F TDS & Taste:

Purpose: Test TDS at point D. This is to confirm if the pre-filters are not serverely clogged with undiesered contaminants.

  • Remove the Clear line from point D (Entry point into the membrane).
  • Catch some water from this line. Test TDS. Record TDS for point D.
  • Do a taste test of water from this line. Record your finding for point D.

Test #3: Point T1 TDS & Taste

Purpose: Test TDS at point T1. This is to confirm that the ASO valve is OK, and is not causing the "funny" taste.

  • Remove the CLEAR line from point T1 (plastic Tee-fitting) .
  • Catch some water from this line. Test TDS. Record TDS for point T1.
  • Do a taste test at point T1. Record your finding.

Test #4: Point G (Tank Line) TDS & Taste

Purpose: Test TDS at point G. This is to test tank water's TDS, and taste.

  • Remove the YELLOW tank line from point G (the other end of plastic Tee fitting).
  • Turn ON the tank valve.
  • Catch some water from this line. Test TDS. Record TDS for point G.
  • Do a taste test at point G. Record your finding.

Test #5: TAP water TDS

  • Get some TAP (unfiltered) water from your sink faucet.
  • Do TDS test. Record your tap water's TDS.

Please give us the TDS number for points: D, T1, G. We need these info to diagnose further.

Reading next