Error - Sensor opened - delete data and start over

I received the error message that one of the sensors must have opened and the instructions that I needed to reset all data. This was a bit upsetting because I installed it about 40 days ago and it was starting to recognize most major appliances and some other items like sump pump and refrigerators. I also installed a dedicated circuit monitor for the hot water tank and furnace. And then a smart plug for the clothes washer. I was tired of waiting. I didn’t trust the error message the first time because I hadn’t been in the electrical panel for weeks and all of a sudden it opened on it’s own. So I waited and about a week later I received another error message so I followed the instructions and begrudgingly reset everything. The good news is that I can start with the hot water tank, furnace and clothes washer identified. It’s been 3 days since the reset and now Sense has detected “heat 1” and 1 of 2 fridges. The problem is that “Heat 1” is one of the elements on the furnace. I recognized the power draw and so when it came on I went top the basement and felt the ducting right about the furnace and it was getting hot. I have the fan always on so as soon as I seen Heat 1 shut off I notices the ducting getting colder. Why is is not detecting this on the dedicated circuit.

I have a lot invested in Sense now and it is still causing issues. The sensors could not have opened on their own and there is a lot of room for them on the mains. Two questions; Why did it give me the error and why is it not picking up the furnace on the dedicated circuit monitor. Both dedicated circuits are 240. I have included pictures.


Hi @charliedearborn, I’m sorry to hear about the frustrations on your end. Have you already written into Support? They will have a bit more insight on what’s going on here and be able to advise on the next steps.

Sorry - I’m a rooky and will go to support now.

No need to apologize! We’re here to help, but limited in our ability to provide insights as to what’s happening in the back-end.

Ok, so what was the resolution from Sense Tech Support?
I have received same error on second day of install. I have tripple checked CTs closed properly for both Mains and Solar. No physical issues there. I haven’t touched my panel since install.

I am not going to believe what sense sent me as a notification about OPEN CT. It is certainly not true.

On top, My Main CTs are not accessible anymore. UTL guys locked the Panel which was open earlier.
Can you please tell me the ultimate resolution you were provided?

Hi Manny1314 - I have access to my mains so I opened it up again and used electrical tape to ensure that they stay closed. I say this but I’m convinced that a CT did not open unless it did it on it’s own. There is a separate cover to the mains and lots of room under that cover. I reset everything and am hoping for the best. I’ve had very good results with using this Sense community and they responded within 24 hrs on the ticket I placed, so the service is good. It’s also a very good idea to give them access to your data. The is the reply that I got from support today.


In checking the original readings from your monitor, I do indeed see that one of the main current sensors was reporting as opened. All of the 240V devices from one phase of your electrical panel were previously reporting less of a wattage gain than the other phase of your electrical panel. This was further confirmed in comparing the readings from the dedicated circuit monitoring sensors and comparing them against the readings from the main sensor readings. The same energy signatures in the main sensors showed less wattage usage than was reflected in the dedicated circuit monitoring sensors. This caused for the monitor to be flagged for having an open current sensor.

In checking the more recent data from your monitor now, I do not see the same issues in the wattage readings as being present, so the issue should be resolved now.

Similarly, there were no issues in the reporting from either of the dedicated circuit monitoring sensors that I was able to see. Both of those sensors were accurately capturing all of the wattage for the related energy signatures. There were no other energy signatures running in conjunction with those that stood out. In this case, the device that you are looking for is likely powered from a different set of wires than what Sense is currently tracking.

Sense Customer Support


Thanks @charliedearborn. That helps a lot.
Ok I see what they use to determine Open CT. Well, that is not necessarily true analogy if you ask me. i.e. I have Two parallel Conductors that feed my Main panel, (See photos), thus Amps flowing through each conductor per phase may not be extremely accurate since impedance of the cable may vary a little bit due to difference in length of each. SO, if they are concluding OPEN CT based on just the 240V load (dryer for an example), it will grab same amount of power in each phase HOWEVER, there might be still a slight change compared to each legs of 240V system due to slight difference in impedance that is involved during the Amps flows through TWO parallel Conductor in my CASE, if that makes sense.
That is my understanding however I am going to wait for Sense team to show me where the problem is. If they tell me the similar story as yours, I am going to ask them for a proof of these differences in the power on each leg.

Thanks for the quick feedback! appreciate it. We learn new everyday!