Issue with 2nd gen contact sensor - "state of sensor unknown"
I got an alert from the Ring app last night that one of my contact sensors had gone offline. I've been getting these lately as I'm coming up on about 5 years since I originally installed my Ring system so the CR2032 batteries need to be replaced (impressed with the actual battery life).
Usually I just replace the two CR2032 batteries and put the sensor back and it's fine. But this one isn't working. It'll blink red when I take it off the window (tamper), but when I press the button it won't flash green. I've tried two different sets of new batteries, and using the "Retry Connection" feature in the app (based on https://ring.com/support/articles/5igrf/Troubleshooting-Your-Contact-Sensor-2nd-Gen), the base station just won't find the sensor.
What else can I try?
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23-02-2026 15:31:27
Responses (3)
Hi @windracer. If you haven't tried factory resetting the sensor, try that next. You may need to remove the sensor from the Z-Wave network, with instructions on that here. After these steps, you'll just connect this device as normal using the Ring app. Let me know if that works.
Unfortunately the pin hole/factory reset isn't doing anything ... I never get any green flashes from the LED indicating it's resetting.
Very odd that I get the red flashes for the tamper when I remove it from the base (or use a small screwdriver to press and release the tamper switch on the sensor itself) but no green at all. I've never had a sensor just die like this but sounds like I need to buy a replacement?
Also, in the app it says to try replacing the CR123a battery, which is incorrect. This is a Gen2 sensor so the batteries are CR2032.
Hi @windracer. Thank you for trying those steps. Since the sensor still isn't working, please reach out to our support team @Ring on Facebook, X, or Instagram to see what options are available. If you could share a screenshot of the incorrect battery being shown in the Ring app, that would be helpful as well.
Here's the incorrect battery info in the app:
I ended up ordering a new contact sensor and it should be here tonight so I'll replace this faulty one. As you can see from this screenshot, there was definitely some battery weirdness (which I didn't get any notifications about) before the sensor just dropped:
windracer
@Caitlyn_Ring, @Justin_Ring ... any suggestions?
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24-02-2026 18:46:17
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