Thanks, Bob, for sharing your puzzle, as I always enjoy a brain teaser. How long is the mystery device on at a time? Sometimes if you zoom way in, you can estimate the times. An easier way is to enable Show on Timeline, in which case the app does the math for you and shows you a summary. Here is an example from my case.
I have two mystery devices: Heat 8 which consistently runs for 15-20 minutes at a time; and, Device 3 which often runs for just seconds at a time. You can also click the View Stats button at the bottom of the device screen, which tells you the average run time. In the case of my Device 3, the reported average is 16 minutes, which tells me that there are some long runs mixed in with the short runs to bring the average up from seconds to minutes.
It may also help if you post a zoomed-in view of one run. The shape of the graph can provide clues, even though the shape is AI generated and not always accurate. I can tell from the view you already posted that the peak wattage of each run is very consistent. Still, we need more clues to help you identify this device. How long has the device been in your inventory?
Do you have any other device guesses? For example, my aquarium heater cycles a lot, and it functions less at night, like your mystery device. This diurnal preference occurs because we turn off the A/C in the living room when people are asleep in their bedrooms. My aquarium heater is on for about 2 minutes at a time, according to its Stats page, and uses 182 W on average.
It turns on, runs for about 2 minutes, then shuts off. It has also “calmed down” a bit from a few weeks ago, when it basically was doing it non-stop all day long. Now, there are periods of no activity.
I have no other guesses of what it could be. We have a number of devices that are on smart plugs that we shut off at night so I have been able to eliminate a number of things that way.
My wife and I are going to try to pounce on flipping circuit breakers but we have to be quick - it only lasts for 2 minutes than shuts off. We will start with the refrigerator to see if. My guess is correct, if we can do it in time.
No Aquarium or the like. So my guesses are limited.
Thanks for the new information, Bob. It’s cool that your wife is helping to try to identify the mystery device. The other members in my household are not interested in my Sense hobby.
Do any of your smart plugs report energy usage to Sense? Putting your fridge on such a smart plug sounds easier than trying to turn it off within 2 minutes of the mystery device turning on. If the same pattern appears in the report of the integrated smart plug, then you would know it is a component of the fridge. I have my fridge on a smart plug, but its profile is very boring since it is the old-fashioned kind without an ice maker. Here is what I see:
My wife opens the fridge door frequently while she is awake, so the compressor runs all the time except immediately after a defrost cycle. The fridge only gets to relax when she is asleep. The point is, however, that if an ice maker were present and superimposed on this graph, it would be as obvious as my defrost cycle.
A two-minute run cycle sounds a lot like my aquarium heater. You don’t have an aquarium, but might you have any kitchen appliances with a stay-warm feature? Does your HVAC system have a defrost system, or does your house have any piping that is frost protected? Either of these might be activating out-of-season due to some defect.
No defrosting system that I am aware of on the HVAC system. For a little bit of additional info, I am in Florida. So no pipe heaters, etc. No other cooling system other than the A/C.
Now for something interesting. Here is the usage from yesterday afternoon until just now:
We had friends over yesterday and we were in the pool. They used a bathroom and a bedroom we rarely go into to get changed. But we have not seen anything different and they would not have turned anything on except lights and the bathroom fan (maybe).