Another Nest bites the dust

While I was playing in the South Carolina QSO party yesterday, I discovered my Nest thermostat decided to flake out and turn the AC on, even though it was saying the AC was off.

It’s not the first time I’ve had a Nest fail on meĀ  before (technically, just the base of the Nest).

No idea if it just happened to be a coincidence, or if it got zapped by some RF while I was playing on the radio. Also a little puzzled as to why the Nest base failed this time and not the other times I’ve been on the radio.

A search of the internet brings up a few forum and email threads that suggest the Nest thermostat base might be susceptible to RFI, probably via RF coupling through the control cable between the thermostat and the HVAC unit.

At the old house, I think the antenna was far enough away that it was never a problem. Here, with the antenna pretty much on top of the roof, RFI into the thermostat via the wiring is a definite possibility.

 

Guess now I need to see if I can add a bunch of ferrites to the wiring.