Sounds like it is dropping off the network and not reconnecting. What wifi adapter are you using and what firmware version (v14 or snapshot)?
Bryan - I wrote a post and then figured some things out and tried to delete it, so I am not sure if what I wrote is still there or not. Anyway I have a specific question about updating my HeaterMeter image. I removed the SD card and put the new image onto it. How to I get the Raspberry Pi 3B to download the new image from the SD Card. The instructions I read only cover the first time which happens automatically. Since I already have an image loaded, how to I trigger the RP to do an update from the SD card?
The SD card is the only source of storage for the Raspberry Pi. If you've removed the SD card and have updated it manually, then as soon as you boot the Raspberry Pi, it will be using the updated image.
To update the image on the SD card while it's still in the Raspberry Pi, you need to login to the HM web config, go to System > Backup / Flash Firmware tab.
From there you can upload the HM firmware you downloaded or you can paste the URL of the correct firmware file based on the Raspberry Pi model you have.
Yep. The heatermeter board, once programmed, doesn't need the raspberry pi to operate. The raspberry pi provides the web interface, configuration control and email + sms alerts to he heatermeter.
You'll notice that if you boot the heatermeter up with no sd card in the raspberry pi that you won't have any web interface.