Using Sense to save energy


Ahh… the joy of owning a home :money_mouth_face:




I thought the same but a Google search turned up a couple of schematics
where the lower element was wired to a ground symbol.
I did see one person on this site observing his Sense was reporting hot
water with 120Vac sometimes.

Alan Kirk GMail


After a couple of weeks, the water heater was found again, but the problem persists. Seems to accurately ID it in the morning, and then in the evening it either misses it completely or only gets half the draw. When it comes on in the morning, there is no solar; in the evening the solar is just tapering off. Completely anecdotal, but curious.


I have yet to get things to start detecting. Just installed last night and got Solar configured today. What i do expect to be able to do is find items which might be using power unexpectedly, like home entertainment items. I have a Projector ceiling mounted on its own power connection. If i find that there is enough of a wasted draw by the sound system, media center device (Nexus Player Android device), ps3/ps4 etc, i could see getting some smart outlets to tie to my Home Assistant setup (raspberry pi 3 + touchscreen + zwave dongle + home assistant python app) to turn off those items when the projector is not turned on.
Then also just trying to find those Always On items that maybe don’t need to be. Really hoping to start seeing data soon. So far just my Solar bubble and if something large like A/C kicks on i see the other bubble.


I had mine installed on Saturday.
it took 2-3 days before anything was detected.
On day 6 and I have my AC, two fridges, gas dryer, and Toaster oven/Coffee maker (combined for some reason. They do use the same outlet).
My Sparky(electrician) was great and tightened all of the breaker wire connections (many were loose). I fixed some outside connections by adding dielectric grease to the wire before screwing them down. 100 year old house so I am sure I have some old, crappy wiring.

I found that my old (pre HDMI) Onkyo amp that we use for the TV(and radio and DVDs etc) uses about 80W if I forget to turn it off with the TV (I may go back to using just the TV speakers). Also, found some basement lights using 130W (They are LED). My wife leaves them on when working in the basement office during the day.

It is great to see real time power changes. Even small ones like plugging in my Iphone (or Ipad) to charge and it shows +12W.


Instead of not using the reciever, I would suggest you use a power saving surge protector. They turn on/off devices based on a control outlet. Plug your TV into the control, when it comes on the receiver outlet comes on. Best part is they are cheap and can be found for $10 on Amazon.

For the lights a simple vacancy switch can be had for $20 and you won’t ever forget them on again.


I plan to replace the receiver this year. Not really sure that I need the amp for listening to a TV. It is a decent Sony so should sound OK without an amp. Also, the TV is on so much during the day that it would probably save me 1/2 a kWh per day.


That’s really peculiar behavior. Is hot water used predominantly in the morning as oppose to evenings? And are the “on” Signatures relative to active use or is it just maintaining a certain temperature? I.e. (120 degrees)
Faulty heating elements would definitely distribute odd as resistance would be increased but I don’t think at half the draw. That seems extreme.
When it is actively heating, is the on time the same as previous times? Or does it run for longer periods?


We have our water heater set up on a timer, it’s a zwave model. On at 5am and 5pm every day. Time of run is dependent on outside temperature - typically 30-45min.

When it’s on, it’s pulling 5k watts almost the whole time, but only about half the time is the whole curve recognized.

Based on some more anecdotal data, I’m almost sure it’s having the most trouble when other devices are running - especially the heat pump. Yesterday morning, the heat pump was running and accurately identified… Up until the water heater came on. The water heater was recognized for a hot second, then both dropped to “unknown.”

I’m commonly seeing problems with fridge shutoff recognition, complicated by heat pump activity. We were gone for a few days (heat pump turned down), and the fridge recognition was near-perfect. Heat pump on - fridge shutoff detection goes down.

I should note - I do not have the halving problem with the heat pump, it gets both phases. However, it correctly detects it just 80-90% of the time.

Wonder how common all of this is?

Here’s the messy fridge:


I have a similar issue and they’re currently working on a resolve.
I don’t have a heat pump, but I have three AC’s, two of which are identical in size & brand. When one system comes on, its detected properly. However; if one is running while the second turns on, Sense gets completely confused.
It cancels out both systems and shows them both as “off”.
Sense also has an issue detecting which Compressor is running at a given time. When my first floor AC comes on, it picks it up as the second floor AC and vice versa.
It appears to be a bug that’s directly related to Compressors.

It’s really tough to determine if it’s causing the water heater issue. It almost doesn’t make sense. Pun intended.
Cross our fingers in hopes of a break through :crossed_fingers:


I suspect if enough people are seeing a problem and report it, Sense will try to come up with a solution.

More data points will be helpful, too - but I don’t see much relief from the heat coming any time soon, so I don’t expect I’ll be able to see many data points without the heat pump running for a while :slight_smile:


Hi @NJHaley,

Have you had a chance to submit a support ticket for the heat pump/hot water heater conflict and the fridge shutoff detection? Just want to make sure we get those issues formally logged for the data science team to take a look at. As you mentioned, the more reports we get, the better data we have for tracking down the issues, so that would be really helpful.

Thanks very much!
Brad (covering for @BenAtSense this week)


I’ll send in a report for the heat pump and the fridge. I try as often as I can to hit “not running” when the fridge is off, but it hasn’t seemed to yield anything fruitful.

One other thing I’ve noticed occasionally is what looks to be a hardware issue: gremlins appearing occasionally related to my solar channel. I was advised to recalibrate, but I’m not sure that will be effective. I’ll send a separate report with screenshots, and hopefully it can be routed higher up the chain…


Great, thank you!!


ME TOO on the well’s pressure tank!

I’m extremely happy with Sense. I would like more devices detected more quickly, but for the good it’s doing me, I’m willing to be patient.


I find the sense to be an very capable measurement device and provides detailed information about the energy uses in what ever it is attached to. The ways it can save money are not just related to energy conservation but can apply to failing motors, water logged well pumps, heat loss from hot water heaters, and defective wiring. I don’t expect the sense to be able to send you a diagnosis yet but the analysis of the data and the power curves, current startup surges and the duration of the device on time (e.g. well water pumps) can tell you what is going on with your devices. There are reports already of users seeing electrical motor capacitors and frequent well pump cycling that the sense doesn’t know how to interpret but a knowledgeable end user can use to great advantage. I have used power monitors from several different suppliers over the years and this one is by far the most accurate and capable one I have used. Watt Vision was attempting to do the appliance recognition but they never got anything to work. Current Cost has a power monitor but it doesn’t measure voltage and the sample rate is very low. This Sense apparatus is what every Smart Meter should be doing and providing detail information to the end user.