topic Re: Error Code E72 in Nest Thermostats

Error Code E72

michaelshoup — Sat, 04 Dec 2021 02:47:31 GMT

My thermostat was working, but I removed the display from the base and got an E72 code after I replaced it. It says "E72 WIRING REPORT No power wires detected. Rh or Rc wires required." For a while the equipment diagram on the thermostat showed that only three wires were connected, and now it shows that just two wires are connected (the G and W1 wires). I know that the Y1, C and Rh wires are also connected - the tabs are indented and the wires are snug. I did not re-wire anything before the error code (I only removed and replaced the display) and the other 2 Next thermostats on my 3-zone system are still working and recognize that all 5 wires are connected.

This seems like an issue with the connector between the display and the base, or could it be something else? Are connector issues common? Can it be repaired, or do I need to replace it? I'd like to try one of my other Nest displays on this base to see what happens, but I don't want to risk getting an error code on a second thermostat display.

I shut off the thermostat by holding the display down for 10 seconds, but the same error code came back after it re-booted. Any other suggestions?

Re: Error Code E72

Denton — Sat, 05 Feb 2022 01:46:33 GMT

this just happened to me as well! how were you able to resolve it?

Re: Error Code E72

Tropicalfnf — Fri, 03 Jun 2022 22:06:23 GMT

Seems to be a common issue. Any solutions?

Re: Error Code E72

LisaGM — Mon, 29 Aug 2022 23:47:39 GMT

I get the exact same issue. We have to remove the unit and plug in to charge then it works. Until next time which goes be moment, days or weeks. My husband a General Contractor in construction so pretty sure the wiring is done correctly. Especially since the 1st power error occurred months after we installed it.