Tamper won't clear after replacing sensor batteries

I used Honeywell 5811 window sensors around my home two years ago when setting up my system. Three of the sensors have recently alerted for low battery - so I got some new CR2032 batteries to put in them. The issue I am having is that once I open them to replace battery I get a tamper alert - but the tamper isn’t clearing once I replace the battery and put the sensors back together.

Any tips? Thanks!

Have you tried activating the sensors since replacing the battery? Can you confirm if they will send open and close signals to the panel?

A couple things may be wrong:

Double check to make sure the batteries were inserted in the correct direction. Coin batteries are easy to flip the wrong way.

If they are functioning otherwise and the panel reports open and close, double check to make sure the cover is installed in the proper direction and fully snapped back on.

I continue to have this problem with all of my 5811 window sensors, even after replacing GC2 panel with GC3 due to unrelated failure (LCD stopped working in GC2).

I spent some time today trying to understand the issue. Your question “Can you confirm if they will send open and close signals to the panel?” is what led me down this path.

I’d replace the battery and no, it wouldn’t send open/close. So I noticed if bend the POSITIVE battery contact on the sensor just a HAIR - like a fraction of a millimeter, the sensor works after battery replacement and open/close/tamper is sent to panel property. I bought Panasonic CR2032s just like sensors originally came with, maybe the new ones are a fraction smaller diameter? Another possibility is the positive battery contact being bent back a little when I pop out the old battery with a screwdriver.

Just wanted to report back in case its helpful for anyone else. Didn’t need to mess with tamper contact, or negative contact - just the positive one. I’d had this issue on multiple 5811s.

If you used the same type of battery it shouldn’t be sized differently, but I suppose it may be possible if they are all the same manufacturer of battery or came from the same pack.

It is more likely that the positive contact was bent a little during removal if you used a screwdriver the same way on them all.

Either way it is a good find! It definitely did sound like a power issue. Thank you for following up! That may indeed assist others.