Direct answer
For the Fitbit Versa 4, device water rating, lock/eject function, seals and prior damage must be respected. First, check exact model water rating and dry it by approved method.
What this covers
- Fitbit Versa 4 (FB523)
- Fitbit device; Google-account migration, onboard GPS, voice, ECG and charging cable vary.
- The specific fault this record addresses: water lock, swimming or water exposure is not working correctly
What it does not cover
- ×The same symptom on a different Fitbit product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
The activity exceeds the model's actual water rating
What separates it Trouble follows swimming, a hot shower or water sports on a device only rated for splashes or shallow water.
How to confirm Check the exact model's water rating against what you did; a 'water resistant' rating for daily splashes is not the same as a swim or dive rating, and hot water/steam can breach many ratings.
- 2
Water lock was not engaged, or the eject step was skipped
What separates it The screen mis-taps in water, or the speaker sounds muffled after, because water was not ejected.
How to confirm Engage water lock before water activities and run the documented water-eject afterward; skipping it leaves water in the speaker and lets the wet screen register false touches.
- 3
Seals have degraded or the device was damaged
What separates it Fog under the glass, moisture inside, or water trouble on a device that has been dropped or is several years old.
How to confirm Water resistance is not permanent — age, impacts and aged seals reduce it; suspected seal damage needs service, not continued water use.
- 4
The device is being charged or handled while wet
What separates it Problems appear after charging or pressing buttons before the device fully dried.
How to confirm Dry the device fully by the approved method before charging or heavy handling; charging a wet device can corrode the contacts and damage it.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- The exact model's water rating versus what the device was actually exposed to.
- Whether water lock was engaged and the water-eject step was run afterward.
- The device's age and any history of drops, which reduce water resistance.
Check the exact model's water rating and dry it by the approved method
ReversibleA splash rating is not a swim rating; hot water and steam breach many ratings.
Use the documented water-lock and water-eject controls
ReversiblePrevents false touches in water and clears water from the speaker after.
Service suspected seal damage rather than charging or reusing wet
ReversibleFog under the glass or internal moisture means the seal is compromised.
Confirm controls and charge only once fully dry
ReversibleCharging a wet device corrodes the contacts and can damage it.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- FB523. Fitbit device; Google-account migration, onboard GPS, voice, ECG and charging cable vary.
- Model — Versa 4 (fitness smartwatch)
- A fitness smartwatch with built-in GPS, heart rate and broad activity tracking, and a MICROPHONE for voice — but NO speaker (no call audio on-watch), and it dropped the ECG/EDA sensors that the Sense line has. So it lacks ECG; the mic works but not a speaker.
- No cellular
- No cellular; notifications/voice go through the phone. 'Cellular not working' does not apply.
- Sensor set
- Heart rate, SpO2 and GPS, but no ECG or continuous EDA — those health-feature symptoms do not apply to it (they are Sense-line features).
- Symptom boundary
- This record covers Fitbit Versa 4 when it water lock, swimming or water exposure is not working correctly. A different symptom on the same hardware, or this symptom on a different Fitbit product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Never charge a wet device, and never assume water resistance is permanent — do not swim or shower with a device whose rating you have not confirmed or that has been dropped.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. Google Fitbit Help publishes this as "Fitbit help". Official Fitbit setup, charging, sensor, notification and sync guidance. What that article does not carry is the model boundary — it is written for a product line, and FB523 is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
Why can't I take an ECG on my Fitbit Versa 4?+
The Versa 4 does not have the ECG sensor — that is a feature of Fitbit's Sense line, not the Versa. The Versa 4 focuses on fitness (heart rate, GPS, activity and sleep) rather than the advanced heart and stress sensors. So the absence of ECG (and continuous EDA) is by design, not a fault or a disabled feature. It also has a mic but no speaker, so call audio plays on your phone.
My watch acts up after I swim with it.+
First confirm the model is actually rated for swimming, not just splashes — and note that hot showers and steam breach many ratings even on swim-rated watches. Engage water lock before you get in, which stops the wet screen registering false taps, and run the water-eject function afterward to clear water from the speaker. Dry it fully before charging, because charging a wet watch corrodes the contacts. If you see fog under the glass, the seal is compromised and it needs service.
Does this answer apply to every Fitbit model?+
No. It is scoped to FB523. Fitbit device; Google-account migration, onboard GPS, voice, ECG and charging cable vary.
What should I record before troubleshooting water lock or swimming?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing water lock, swimming. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Do not charge wet devices or assume water resistance is permanent.
Answer for the exact device and software version shown above.