Hi Bumph1,
Thanks for reaching out. I'm sorry for the delay. H72 message meant that the power to your Nest Thermostat is off.
You can follow the guide below:
1. Check the thermostat power cable, plug and power socket.
If you have a Google Nest Learning Thermostat on the Nest Stand:
- Make sure that the Nest power cable is fully inserted into the
power plug and that the plug has been pushed all the way into the
wall socket.
- Check that the wall socket is switched on.
Note: We recommend plugging your thermostat into a socket that isn’t controlled by a wall switch to prevent accidentally switching it off.
You can also double check that the socket is delivering power by plugging in a lamp or other electronic device and turning it on.
2. Make sure that the display and power cable are fully seated.
- Pull the display straight off.
- Check that the power cable is fully inserted into the
power port and is routed correctly through the groove in
the base of the thermostat.
- Line up the display connectors and press the display
firmly back onto the base. You will hear a click and the
display will lie flush with the base when it’s properly seated.
3. Check the fuse box
- Check the fuse: It’s possible that the fuse controlling power to your system isn’t properly seated or is blown. Re-seat or replace it as necessary.
- Make sure that the switch is set to 'on': Sometimes fuse switches can be tricky: you may think that you've flipped a switch back on, but it might not have been pushed all the way.
- Try flipping the switches that control power to Heat Link and your thermostat off and then on again.
- You can also check power on the socket that the Nest thermostat is using by plugging in a lamp or other electronic device and turning it on.
4. Contact a Nest Pro
- If you’re still not able to fix the problem, contact a local Nest Pro, who can properly diagnose your heating system and your Nest thermostat.
Best,
Jenelyn
