2GIG DW10-345 Sensor Thinks It's Open

Saturday at 10:08 our 2GIG alarm panel at our PA location sounded off and showed loss of supervision on one door contact.

Through the entire sequence below (through 12:36) the panel continued to show the sensor as offline/open, even when it wasn’t. However it did recognize tampers and end of tampers. After changing batteries twice I finally gave up and bypassed it, since we were leaving that location and I didn’t trust the sensor.

Note that the 12:05-06 entries suggest the sensor hiccupped and went back to failure mode, showing the door as open when it wasn’t.

Time Alarm.com logged messages
10:08 Offline
11:25 Back online
11:26 Opened, tamper
11:27 End of tamper
11:38-43 Two more tamper/end-of-tamper
11:55 Sensor-left-open alert
12:02 Bypassed
12:05 Closed
12:06 Sensor-left-open restoral, Opened
12:36 Sensor-left-open alert
14:11 Closed, Sensor-left-open restoral

Since 14:11 Saturday the online status has remained closed, but I left it bypassed. Since I’m not there I can’t see the panel.

Nothing changed about the sensor mounting, location, or any other environment variable.

I’m going to change that sensor. I’m just curious to know if you’ve seen something similar before. What puzzled me is the panel thinking the sensor is continuously open, but still knows if there’s a tamper.

If you have any other insights, I’m listening. At your convenience, and thanks in advance.


Are the tampers actual tamper events? Were those times you opened up that sensor housing?

Offline has plenty of possible causes and is a common status. It would be fairly normal to see an offline sensor remain open if it closed and couldn’t update its status to the panel due to signal.

Is the time at 12:06 representing an actual event where you opened the door?

It could also be a failing sensor radio, so replacement may not be a bad idea. I would test if another sensor has the same problem in the same place.

OK Jason, and thank you.

The tamper alerts were real. I actually tried three different sets of batteries just to be sure it wasn’t really a low battery problem. (Since I was leaving that day.)

I can’t be 100% certain I didn’t open the door at 12:06, but I don’t think so. My distinct recollection is that I bypassed the sensor as the last resort, after I exited that room and locked it, and did not return.

This sensor is in the basement mounted (adhesive) on a steel frame with the magnet on a steel door. It’s been that way a number of years and this is the first occurrence with this symptom. So I have no evidence the presence of steel is the problem.

I’ll consider a sensor swap and test if I’m there for a longer period of time. Otherwise I’m just going to replace it.

Thanks for your help. I’ll update this with a result after my next trip out.


P.S. The sensor still shows as closed and bypassed. The last event was the restoral at 14:11 Saturday.

Hi Jason. Tuesday I replaced the switch on this metal door. I closed the door, and immediately afterwards it did not register that the door had closed, and then issued a Sensor Left Open notification a few minutes later. I opened and closed the door, and then it registered, and appeared to be OK until today.

Today the sensor issued a “Malfunction” notification and went offline. So that’s the second sensor to do that in this location.

I know it’s a metal door in a metal frame, but the original sensor was working without issue for five and a half years. Now all of a sudden two sensors aren’t cutting it. Nothing has physically changed in the house, which for us is a part-time location. Got any thoughts on this?

I’ve read other posts about metal door issues. Place tape or some other insulator between the components, or use a separate contact type or straight magnetic switch on the door, and have that use the DW10 mounted in a non-metallic location simply as a transmitter.

Other than those two techniques do you know any other solutions that might apply?

Thanks in advance.

It’s certainly strange that it worked in that location for so long and now it’s not working reliably with 2 different wireless sensors. I don’t see any obvious solutions to suggest. Metal doors can be tricky.

Is the metal door blocking the direct line-of-sight between the sensor and panel?

One thing you might try is to take the sensor & magnet off the door & frame and experiment with the exact location and orientation of the sensor by simulating opening and closing while holding the sensor & magnet in your hands. Does it reliably report open/close without going offline when you hold it in your hands in the current location? What about when you move it away from the door to different locations nearby? If you can find a spot where it always works reliably then you at least know you can mount the transmitter there and run a short wire to the door using a wired sensor.

If you can’t find a spot where it’s reliable in that room, is that sensor working when you take it into other rooms? You might even try these experiments with both sensors and look for a reliable pattern that hopefully uncovers the cause of the problem.

Another thing to consider is whether the panel itself, or it’s antenna, changed location or orientation. I assume it didn’t but just trying to cover all bases since problems can exist at both the transmitter and receiver, as well as in between.

Sorry for the difficulty. It’s really frustrating when stuff like this happens.

One thing to keep in mind while thinking through all the variables is that the sensor-left-open notifications are Alarm.com rules and happen in the cloud not on the panel so they can be ignored when troubleshooting the sensor and panel. We can just focus on the open, close, tamper and malfunction events.

OK Ryan. Thanks for that distinction. And I take your points about varying the sensor locations, and the trickiness of metal doors and frames.

The sensor/magnet is mounted on the metal door and frame, in the basement (the panel is on the first floor), and the orientation is such that the metal is between the transmitter and panel. I suppose I could wonder how it worked reliably for five and a half years!

I have a simple N/C magnetic switch and magnet, so I’m going to try a transmitter mounted on the sheet rock above the door and using the external connection to monitor the door status. We’ll see how that does.

One question: Aside from the unit id #, do I have to change anything about the loop 2 configuration in the panel for the sensor/transmitter?

I’m assuming that when connected, the external contact is in parallel with the magnetic contact inside the transmitter.

If you are going to use the same sensor but instead use the wired input so it acts as the transmitter for a wired sensor, the ID would stay the same but the Loop number must be set to 1.

Loop 1 is for the wired input. Loop 2 is for the built in reed switch.

Thank you Jason. Yes, I see that in the Quick Programming guide. It’s still question 1, RF Sensors, and everything would remain the same except for the Loop#. And I see the three options for that, where 2 is specified for the DW10 internal switch, and 1 is used for “all 2GIG products”, which in this case means a DW10 using the external contact connection.

One more question if I may. I have ordered a 2GIG Takeover kit for my primary location to transfer wired zones to the 2GIG panel. Is the programming for that Takeover unit and its zones what they’re referring to in Question 2, Wired Sensor Programming?

No, Question 2 is referencing the 2 hardwire inputs in the panel terminal block.

See an install/programming guide below:

Hello again Jason and Ryan. With regard to the flaky sensor on the steel door and frame:

I moved and mounted the same DW10 sensor to the sheet rock about 8" above the steel door jamb. I then mounted a classic magnetic contact switch to the door and jamb, and connected it to the loop 2 contacts inside the DW10.

I immediately got solid open/close responses for the next several hours that I tested it. And since then (about 6 days) there have been no offline or other messages. The system has been armed the whole time.

I’ll update this again in maybe a month, after we have a few more visits to that house. But I suspect the issue is resolved.

Why, after five and half years of flawless operation, the connection went flaky with two different sensors I’ll never know. One of those two is the one now in service.