Vampire Drain - BIG

I have had Sense for about 2-½ years. For most of that time I have had an “always on” reading of ~1400 watts which is about 45% of our total consumption. It goes down very slightly in the summer but is otherwise constant. Yesterday I went through turning off all the circuit breakers but could not identify the source. I have an aux generator of 45KW and wondered if it might have a crankcase heater of that magnitude and which bypassed the circuit breaker panel but I can feel no warmth around the engine,

I’m glad you are paying attention to the data from Sense to help track down vampire loads!

Have you tried the Always On Estimate feature of Sense to list known devices that are in constant use? Read about that feature here: What's new in v37 (iOS/Android) Other users have listed their devices on this thread: What Are Your “Always On” Devices? In any case, I doubt your total of known devices reaches 1400 watts, so your question stands.

Turning off circuit breakers is my first suggestion. When you tried that, did you watch the Always On bubble or the main power meter? Note that the Always On bubble won’t change unless you leave the breaker off for about 30 minutes. The main power meter will change instantaneously, so it is recommended that you watch that instead. Try experimenting with breakers when most of your known loads are off, so it is easy to identify when you get to the right circuit.

As for bypassing the circuit breaker panel, I don’t think that is your case. If Sense has identified the Always On, then the device in question is after the clamps from Sense go around your mains, which is typically right at the top of your panel box. Also remember that it might not be one big vampire, but two or more smaller ones that add up to the missing total for your 1400 watts.


Have you checked computers? My 2011 tower uses ~150 when on with no display on and all SSDs inside. My 2012 laptop also likes to process something even when it’s lid is close and thus it’s asleep. Regularly, the body of the unit is warm-to-hot when it’s plugged in. Again, those aren’t going to get you to 1400w, but they’re going to be bigger than most vampire draws.

For the community, correct me if I’m wrong, but is vampire draw as we knew it still a thing? I always thought they were loads of like 20w. I tested unplugging each component in my entertainment center and found that each device (55” UHD TV, Xbox, receiver, AppleTV, etc.) used like 1w when off. Sure it’s something, but again, not big by ANY means. Do modern electronics still have vampire draws.

I believe that depends upon how you define “vampire”.

Strictly speaking I think you could say a vampire load is a useless one that, if the electrical/electronics where more carefully crafted, would be as low as physically possible at the time. Often these loads in wallwarts and other transformers are not controlled to be truly OFF because the electronics adds cost and complexity. As time goes by the threshold for “vampire” has lowered because the definition has become more complex.

  • Is a TV on standby uselessly using power?
  • Fridges and freezers are more efficient these days because they use DC inverter powered compressors that are basically always on and running to match (in cooling power) the energy gain of the refrigerated box. But if the fridge knew (through Sense perhaps, and RT-PMP-like control) that it was “on vacation” because the house is unoccupied or it was aware of the weather would it’s control electronics be crafted differently? HVAC is another example of this.
  • Lightbulbs have gone from 60 watts standard incandescent for a certain lumen level to more like 10 watts or less and they start to incorporate energy saving features like built-in motion detection that, when you think about it, have what may be considered, in the future, a vampire load.
  • The classically vampiric doorbell transformer is replaced with, say, a Nest or Ring doorbell with motion detection, IR illumination, streaming camera and so on and the net result, upstream, is significant energy use outside the house circuit as well. Can the vampires be virtualized?

1400 is a big “always on” number, and worth tracking down. Mine is less than 10% of that number, although I’ve aggressively managed it down.

With a number that big, I’d start with the opposite approach. Turn off everything not “always on” in the house, then turn off all of your individual circuit breakers.

Turn on each circuit breaker one by one, while watching the power meter. Wait a couple minutes after you turn each one on to see if anything powers up. Try to keep track of anything material on each breaker.

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Not that it happens in the same way, but if you’ve had a blackout in the past you can perhaps look back at the Sense power meter to get some hints as well.

I haven’t seen much talk on here about doorbell transformers, but I’d believe it. I haven’t ever thought about, nor certainly looked into, my doorbells, but I have two buttons and two chimes. I was at a relative’s 1950’s house the other week, and besides their ancient looking fuse box, they have at least two doorbell transformers still powered on despite only having wireless doorbells now-a-days. I thought about how much energy they were using, but didn’t even know how to open the fuse panel (where one was mounted) or which of the 10 breakers they were connected to.

@Beachcomber your Always On device/bubble is calculated independently from your Always On estimates, and since Always On is a running calculation (not static, like estimates), I’d expect it to change pretty frequently.

As a reminder, your Always On is a calculation of the lowest power of each of your mains, added together, where “lowest” refers to the 1% bin of the observed wattage histogram over the previous 24-48 hour period. It is updated every half second, though most users will not see significant real-time changes given the 48 hour lookback window.

Always On estimates are comprised of devices you’ve listed in your home that are Always On. If it’s always higher than the Always On bubble wattage, I’d revisit your always on estimate devices and see if there’s anything there that isn’t truly Always On. If Always On estimates are usually pretty close to your Always On bubble, I’d leave them as is.

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Whatever it is, it’s costing you enough money to make it worth the effort to track it down. When you shut down the breakers were you watching the real- time data or the “bubble?” The real time data will be your best bet.


I wanted to revisit my comment about modern appliances and vampire drain. My 60w MagSafe power supply from like 2014 uses 0.1w when no laptop is plugged in. A consumer level Black & Decler drill power supply uses 0.3w with the drill not plugged in. My 2004 Black & Decker 12v battery charger uses 3w with no battery plugged in! I for sure am going to keep that unplugged from now on.


I got a pair of Kasa plugs a few days ago to help me track down sources for my 225 watts of always on. I ran some quick numbers and at my rates (~$0.12 / kWh) the always on watts is roughly my annual cost. So 15 watts of always on costs about $15 per year. And if I use a $15 smart plug to eliminate/control it my ROI is about a year.

If you can find your mystery load (likely 1000 watts or more) you could save $1000 a year.


1400 watts… That is like a space heater or a window AC unit. A generator block heater should be closer to 60 watts and should be on a thermostat. I would almost say a 1000-1100 watts of that is something bad wrong… like a stuck motor without any type of thermal overload/ protection like an attic fan or something you wouldn’t notice. Maybe a heating element in a hot water tank stuck on. I think we have even seen on this community site the hot water tank circulators’ check valve cause the circulator pump to run all the time and also make the hot water heater run excessively.

This is well worth getting a multi-meter with a CT clamp or at least flipping the breakers one by one like others suggested will also get you to the correct circuit… This is like 720kwh per month, not sure your kWh rate, but at 14 cents that’s over $100 a month… or $3,000 over 2-1/2 years.

Another thing to look at is a (failing) well pump. I had a huge 2000w always on load that predated installing sense. After a month of use, and another high utility bill I decided to start powering down the house circuit by circuit while watching the power meter. One of the first items I tried was the well pump and this resulted in a big drop. Unfortunately, the pump would not restart properly to provide pressure (and I did this on a weekend in the winter - bad choice). As the pumps fail they can get to a state where they cannot create enough pressure to turn the pressure switch off and just run continuously. Pump was replaced and now my always on is <400 watts. It would be nice if there was a preconfigured device for “submersible well pump” in Sense.