Another mystery device


Just one zone on the house and no dampers in the system. I have an Ecobee3 thermostat and have the fan option turned off so it should only be turning on when the furnace or A/C is running but there is an option to run the fan for a certain period of time during each hour but like i said i have that option set to off.


I wonder is your variable speed blower is detected as separate devices depending on soeed


I’ve had the motor 2 turn on and off even when the furnace/HVAC fan wasn’t running and its not running the fan but when it did it turned on and off this morning i could clearly hear the fan speed up and slow down respectively.


Another thing that could affect fan speed is heat strips. But if tied to a 20amp breaker would be awful small.
Keep in mind that more than one device could be reflecting as motor 2. You could have the fan triggering and it being conflated with something else


@kevin1 asking about zones could be correct as the damper moving one way can give the illusion the fan speed has changed. If it’s closed off down one duct and open on another, the velocity will change and you would hear it


No dampers in the HVAC system


If you have a heat pump then there are time when the unit outside will run and the fan will not blow. When it’s in a defrost cycle. But it can go either way. The fan may or may not run if compressor is in defrost cycle and there is a call for heat.


I think i may have figured out what the mystery device is. My furnace is a gas furnace without a pilot light and i think it might be the power ventor fan that is kicking on and off and venting the gasses out of the flue.


That’s great @mike_gessner
Are you thinking it’s on that 20 amp breaker?
Those fans are usually not very high wattage and typically are less than 2 amps or around 150-240 watts.


The power ventor fan is absolutely on that 20A breaker and its supposed to be really nice on sunday so i am going to kill power to the furnace for testing to see if motor 2 turns on when no power is applied or if i get bored before Sunday then i just might go up in the attic for a little bit and see if the motor is turning on when sense is detecting it.


If you were in the attic and could force the furnace on while your at the unit it would be easy to tell. I think you said it was a beer unit so it’s probably a “draft inducer” and comes on just before the furnace ignites.
You’ve had some really great detections at the individual component level. I have not and it always makes me wonder why we all have such differences.


Its a Goodman GMP075-3 furnace but the label on the outside says Janitrol


Goodman also makes Amanda and Janitrol
I have a Trane inside and American Standard outside. It’s just like your situation and same manufacturer. As long as it’s a “matched” system it’s not a problem.


What i mean is the tag on the inside of the furnace says Goodman and the model number is GMP075-3 but the brand label on the outside of the furnace says Janitrol which was part of Goodman



Where they have exactly the same models just branded different, it sounds like it’s just the cabinet used had the wrong label. Does the Janitrol label show a model number?
I’m assuming the Goodman label inside has the model and the outside label is just the brand with nothing else.
That’s what is shown in the pics but I see a label under Janitrol


The label under the Janitrol label is just the warning labels on the outside and the Goodman label with all the info and model number is on the inside frame.


Since you got up in the attic, we’re you able to test motor 2?
Off topic; it appears that label is exposed to a lot of humidity. If the attic isn’t ventilated enough it will affect your cost mainly in the warmer months.
I had a similar problem and had to add ventilation


No i took those pictures earlier and didn’t see if it was the power ventor or not.

The label was like that when i moved in so not sure if the previous owners were experiencing high humidity or not but my house does have soffit vents and ridge vents and I’ve already started adding rafter vents with the built in baffles to prevent the blown in insulation from getting down in the soffits. I also have two rolls of Attic Foil radiant barrier that i am currently working on getting installed in the rafters of my attic to help keep it cool during the summer.


Running 2 hots into a HS110 does not fry them. I use 2 of them on 240V, one for each of our EV’s, both of which charge at 16A.

They work perfectly.

I’d put money on the fact that aside from minor internal differences to accommodate different physical plug styles around the world, the guts of the actual hardware is little changed aside from component placement. They are effectively, likely many electronics nowadays, dual voltage out of the box.