12-05-2022 12:37 AM
Hi,
My Nest thermostat suddenly went off and the scree is black. My app is showing it off line.
I have taken it off the wall and put it on charge overnight the reattached it to the wall mount and it is now lit up but showing H72 ‘the power to this thermostat is off.’ I’ve check my fuse board and all breakers are in.
can anyone help?
12-05-2022 04:36 AM
You need to use a multimeter and test for 24v ac power on the red wire to C wire.
If no power possibly the transformer in the furnace went bad.
12-07-2022 11:18 AM
12-11-2022 02:44 PM
Hi there,
Thanks for assisting, Mel.
@Kbro1, I'm checking back in — how's it going? Still need our help? Let us know so we can assist you right away.
Thanks,
Mark
12-12-2022 02:52 PM
Hi Kbro1,
I'm checking in to make sure that you've seen our response. If you have any further questions or concerns, please let us know before we lock this thread in 24 hours.
Regards,
Mark