Sensor Left Open when not open

Over the last few days, I’ve seen an increase of Sensor Left Open on our front door sensor when in fact it is closed. It has happened sporadically in the past, but now seems to be increasing in frequency. (We just installed our system in July). It is a hardwired recessed magnet sensor and it is flush to the surfaces with minimal space between the contacts. We have a HW16F and it’s about 30 feet away from our IQ Panel 4. Should I be looking at the sensor as the cause or maybe the panel or the HW 16F? What are some things I can look into or try to fix?

When the door closes later, is that because it was opened and closed again, or does it just close without touching the door?

With a wired sensor there could be a variety of causes. If it is not misaligned and you are certain the sensor is able to close properly, these are some things I would look at:

  1. Old wired systems frequently group sensors together with similar purposes to save on the number of zones needed. Wired panels usually come with 6 or 8 zone inputs. Sometimes in addition to grouping windows in series, installers might group two or more entry doors together. Especially if this is a home you moved into recently , double check whether or not multiple doors open that zone.
  2. Check wiring. remove the sensor wires at the HW16, cut and expose fresh wire, then reconnect them.
  3. Double check if the door has some wiggle room when closed. Seasonal changes cause materials to swell and contract slightly, and wear and tear over time can make it so a door doesn’t sit as flush as when the sensors were installed, or allow it to move a bit while closed.
  4. Is it a surface contact or is it recessed in the door? Double check the wiring at the sensor and make sure it is not loose.

Thank you for the insight. It’s new build home, one year old. We have to open and close the door again to get it to be detected as closed. They did have windows and a couple doors grouped into 7 zones, but since I had 16 zones to work with with the HW16F, I separated every wired sensor into their own zones. The sensor is recessed and installed flush and is aligned. I’ll check on the other things you’ve provided. In the meantime if anything else comes to mind, I’m all ears. Thanks again!

One thing you might try is to test the sensor while disconnected from the panel. Disconnect the wires from the panel and connect them to a multimeter or ohmmeter and measure resistance. Have someone open and close the door while you watch the meter. When the door is open you should see near-infinity ohms (it may say overload) and when the door is closed you should see near-zero ohms. It should be reliable and immediate. If you see anything else then it’s a problem with the sensor or wire.

We have to open and close the door again to get it to be detected as closed.

Does this problem only occur on this one sensor zone? If it never occurs on any other zone, is this the most frequently used sensor?

If you open and close other sensors more often than you typically would, as a test, do you see other sensors sometimes having the same issue with updating status?

Is it always that it reports open when closed and not the other way around? Does it ever report closed when open?

If you only ever see the issue on this one sensor, and the error is always open when closed instead of ever the other way around, I would presume the issue to be with the wired sensor itself, it is unable to close its reed switch properly, so if it is aligned and spaced properly, it may need replaced.