Cleaning grey water tank sensors (to avoid faulty readings)

Modified on Mon, 11 Mar at 3:42 PM

The grey water sensor in INTERSTATE motorhomes, along with other makes and models, can sometimes provide inaccurate readings due to grime build-up on the probes. To address this issue, a thorough cleaning process is necessary. Follow the steps below to rectify the grey water sensor problem and ensure accurate readings.


  1. Empty the Grey Water Tank: Park your INTERSTATE motorhome in a suitable location for dumping grey water. Open the tank valve and allow the grey water to drain fully.

  2. Rinse the Tank: Close the tank valve and connect a hose to fill the grey water tank at least 3/4 full with fresh water. It can also be effective to flush the whole system by running the hose and allowing water to drain down the kitchen sink. Open the tank valve again to drain the water, effectively rinsing the tank.

  3. Add Cleaning Solution: Measure and add an appropriate amount of cleaning solution to the grey water tank. Ensure the solution is specifically designed to break down grime and deposits. Thetford 'Grey water fresh' cleaner is a good option. You can see it here.

  4. Fill 3/4 Full: Once the cleaning solution is added, fill the grey water tank again to at least 3/4 full with fresh water.

  5. Drive for Agitation: Close the tank valve securely. Drive your INTERSTATE motorhome to allow the cleaning solution to move around in the tank and agitate any buildup. 

  6. Allow Time for the Cleaner to Take Action: Park the motorhome and let it sit for a while, allowing the cleaning solution to break down grime on the sensor probes.

  7. Drain and Rinse Again: Return to a suitable location for dumping grey water. Open the tank valve to drain the contents, including the cleaning solution. Rinse the tank once more by filling it with fresh water and draining it again either by filling directly at the inlet point or by running a hose to the kitchen sink to once again rinse all connected plumbing.

  8. Checking Sensor Readings: Check the grey water sensor readings to ensure accuracy. If the issue persists, repeat the cleaning process or contact our support team for further assistance.

  9. Regular Maintenance: Implement a routine grey water tank cleaning schedule to prevent future sensor issues. Use appropriate cleaning solutions as recommended b.


By following these steps, you can effectively rectify the grey water sensor issue in your INTERSTATE motorhome and maintain accurate readings for better monitoring of your grey water tank levels.

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