Repeated short spikes - looks like an electricity comb

I’ve seen this over a few days, typically in the evening. Note the time scale … I can’t figure out what’s coming on, spiking for just a few seconds, and then off … lather, rinse, repeat.

I have a few other weird waveforms, but I’ll start with this one. Thanks to anyone who can help identify.

Do you have someone in the house with an electric heating pad/heating blanket? My sense shows a similar trend when my wife turns hers on…usually lasts 30-45 minutes until it times out (depending on brand…).

Let us know if that is the case - very interested in device profiles!


Yes, I also think that looks like some sort of small heating device. A fish tank water heater? Soldering iron? Hair Straightener? Keurig? Please report back when you find out what it is :slight_smile:

Could also be something like a wax melter.

My washing machine agitator motor gives me little spikes like that. Do you do laundry at night?
Edit: on closer inspection, my washing machine comb spikes are also followed immediately by larger valleys than what yours shows, I think the others are right, most likely something much smaller.

Hi! Thanks everyone for chiming in - you are a helpful group. She/we do have an electric blanket. As a test, I turned it on, and watched the graph. No real change. Disappointed, I went and did something else. I looked at it again ~20 min later, and I see the ‘comb’! It must’ve (?) took time to heat up, and this is the electricity draw to sustain the temp.