Three-way light suddenly on all the time

[Sachelis]

I installed a dozen+ Insteon devices and a ISY 994i several years ago (thermostats, lights, shades, etc). It has worked wonderfully. However, I have two switches configured as three-way switches to control a hallway light that, starting yesterday, the light is always on. I suspect a switch may have gone bad, but I'm unsure how to troubleshoot it.

Here are some details:

• In the Admin Console, I **saw** the two switches as a 2477D and a 2477S. However, they now both appears as S's! Maybe I was dreaming. I restarted my browser and re-queried all devices.
• If I manually turn off either switch at the wall, the light turns off for only one second.
• In the Console, if I set the "North" switch to Off, the light turns off for about one second (and the state in the Console shows Off for that second and then returns to On).
• In the Console, if I set the "South" switch to off, the light does not change (although the Console does toggle between On and Off and stay in the new state, and I hear the physical switch click).
• Maybe meaningful, none of the tiny dimmer LEDs are illuminated on either of the physical switches.

Based on what I know (not much), I'm thinking what I am calling the North switch is bad (always on). Two questions:

• Is there any other troubleshooting I should try?
• How can I tell which is the master/slave (apologies for old-school terminology) and how can I disassociate them?

Thanks!

[gzahar]

- Check (find/replace) if any of the switches are in a program that could be turning the light back on.  You could also sort the programs (summary tab) by time last run to see if any programs run around the time the event happens.

- I think it is right click on the switch(es), diagnostics, then show device links table.  Once it loads, do a compare to verify it matches what ISY thinks it should have.  (there are some cases where a mismatch is OK.  Not sure how to explain that one easily, but there is usually one or two bits of the values that can be off for hop count or something like that.

- You should have a (3-way) scene with both of the switches as controllers.  Verify when you look at both switches in the scene tree that the other switch is set to turn on as part of the scene.  There is no master/slave, both should be controllers (show as red).  Although one will actually be connected to the load.

-You can also delete the scene and recreate it.

- If you want to know which one is connected to the load.  Delete the scene and see which switch actually turns the light on/off.

[Sachelis]

Thanks Gzahar.

I initially though it might be a rouge program, because that light does turn on when the garage door is open. I disabled it and the problem continued.

Deleting the scene was a great idea too (after getting a backup... too bad you can't temporarily disable a scene). That proved that it wasn't a problem with the subordinate switch.

That left one option, that the "north" (aka master) switch was bad. I replaced it. The rest of the story is it took an hour+ to change all of the programs that referenced this switch and update Alexa and the Alexa portal.