My TDS meter isn't working — troubleshooting guideUpdated 2 months ago
The meter won't turn on
The most common cause is a dead battery. The ZeroWater TDS meter uses a LR44 button cell battery. To replace it:
- Remove the cap at the bottom of the meter
- Remove the old battery and insert a fresh LR44
- Reattach the cap
LR44 batteries are widely available in supermarkets, pharmacies, and online.
The meter shows a reading but it seems wrong
- Filtered water reads the same as tap water: The filter may be at end of life (TDS 006+) or not seated correctly. Try reseating the filter.
- Tap water reads 000: This is very unusual but possible if your local water is exceptionally soft. Confirm by testing a known mineral water — it should read above 000.
- Readings jump around: Dry the meter probes thoroughly, then re-test. Moisture on the outside of the probes can interfere with readings.
The meter displays "HOLD"
HOLD means the hold function is activated — the meter is locked on its last reading. Press the HOLD button once to release it.
The meter display is faded or hard to read
This is a sign of a low battery. Replace the LR44 battery as described above.
Still not working?
If the meter is still not functioning correctly after trying the above steps, please contact our customer service team — we're happy to help.