Need help identifying this high draw device

This is my first post - so be gentle! :wink:

I’ve had my Sense for about a month, and yesterday it identified a new device and called it Heat 3. Sense detected it once on 10/6 where it ran for 1 minute, then nothing until 11/21 - 11/22 where it ran 30 or so times (for very short periods), and hasn’t been recorded since then. It’s a pretty high draw item, drawing 3000 watts during the starting surge and 2200 watts after that. Based on that I’m thinking this has to be on a 220V circuit? My largest 120 breakers are 20A. Sense has already identified my well pump which draws less than this and has a totally different signature. Here is the Sense list of guesses:

Here is a zoomed in display (4am - 4:30am) of the Heat 3 power meter the morning of 10/22. Even if I zoom all the way in they still show as single vertical lines with no duration:

Then I went to the Now (total power) display, backed up to the same timeframe and looked there. Here is a similar timeframe view (4am - 4:30am) total power:

And here is that same display zoomed in all the way:

Hopefully that gives enough data for someone smarter than me to diagnose what this might be.


With an approx 5 min cycle while running it seems like it would be related to something like a pump. Just because Sense identified your well pump doesn’t mean you won’t get misidentified artifacts from that or other devices.

As you say, it’s likely a 240V device due to the wattage. The thing to do is look at, say, the well pump signature and line it up with “Heat 3”. ID all your 240V devices and account for their maximum wattage.

And remember not all short-duration power spikes are going to necessarily be from 240V devices … “Saw” (at the top of the Community Names list that Sense is suggesting) is an indication (despite “Heat 3”) to me that Sense is perhaps pattern matching with a more complex signature than it is presenting you with because the device is likely not the most common in the Sense pool. 120V “saws”; pumps & other motors all have high initial power spikes that Sense could match but meanwhile the on/“off” identified spike is just the device starting … obviously it’s still running after that but Sense hasn’t recognized that.

What other devices are running before, during and after? What part of the country do you live?
What major appliances/fixtures do you have?


No idea what else was running at that point, I wouldn’t have expected much of anything during that time of day. I only have 3 220 breakers - a well pump that draws a1700 watts and appears to be accurately identified in Sense, an air conditioner which shouldn’t have been running, and a sub panel breaker that powers my shed. I have a propane boiler which supplies domestic hot water and forced hot water heat. live in New Hampshire.

My money would be on lining up the well pump signature with Heat 3 and the Mains Power Meter and looking for patterns … or waiting for Sense to do the same.

Then again a lot can go on in a New Hampshire shed!