HVAC fan not always detected


I have my HVAC fan set to run for a few minutes every hour. My sense unit has just learned my fan motor. However, it is not detecting it when the condesor is running. Any thoughts?


I’m the opposite. Our two condensors have been discovered but the two air handler fans running for 10 minutes every hour are yet to be discovered.


I guess I am most curious as to why the “digital signature” of the fan would change based on if another divice was running or not? It is just a single speed motor.


My system does the same thing.
Not sure if the blower runs faster or slower when ac is running. If the blower is running before the ac turns on then it stays.


The signature may or may not change, what’s important is what’s going on in the background when it fires up. It’s like listening to a friend talking in a quiet room vs. at a concert or something.


Good analogy, and in some cases it’s like the difference between a dinner table conversation and a jammed full rock night club. In the latter, the desired device signature gets totally washed out in the background noise.

That’s exactly why Sense doesn’t work for me. I have one device with a very distinctive but complex signature. It’s a Franklin Electric constant pressure well pump. Whenever it runs for any reason, the power cycles up and down on about a 2-3 second cycle, but with a magnitude depending on how much water flow is being detected…sometimes the power cycle is from about 50 watts to perhaps 100 watts, but when full flow is required it cycles from 200-300 watts up to over 800 watts. For some reason Sense can’t handle (or even detect) such a signature (even though visually it jumps out at you), and on/off cycles for pretty much everything else get lost in the “noise”. This means that even detected devices loose on/off detection whenever the water is running. And, so much for things like dishwasher, clothes washer, etc.


Our appliance that muddies the water is our heat pump, which runs almost continuously from now until October. Those months we lose a lot of data on other appliances because they’re not picked up as consistently.


Yes indeed.

Our heat pump is a Climate Master geothermal unit, which provides all our heating during the winter…it’s still in that mode because up here in NH it’s still getting chilly at times…and cooling during the fairly short summer. Since it depends on the 50 degree water 500’ down, whenever the geothermal is running, so is the constant pressure well pump….which is the “noisy” device. Actually, the well starts about 20-30 seconds before the geothermal heat pump and continues after it for a similar duration, plus of course it runs whenever we are drawing any water…even a teacup causes it to run.

The geothermal heat pump itself is actually pretty clean, and both our original Sense and its replacement both picked it up. The problem is that the constant pressure well masks the heat pump signature somewhat, so the registered power is not correct. Fortunately, I also have a WelServer system that monitors the deep well, geothermal, radiant, mini-duct, aux hot water (mostly we get that from the geothermal) heater, solar, ERV, etc…all very accurately. I bought Sense to track all the other users of power, but it hasn’t been able to do that for us.


I have a 3 year old Trane XR15 heat pump with a variable speed air handler. When they were first added they worked properly. Now the air handler is showing 2kw almost the same as the heat pump. I don’t think the variable air handler should be using that much.