My base ################ is not working. Error code wiring rh is not connected

[joachimhilmeric]

Aerial #: ################

Although the wires are connected properly, my thermostat still shows the error message and I neither can operate the system via the thermostat itself nor through the app 

[sicsacol]

Hi @joachimhilmeric,

Thanks for posting in the community. I understand your Nest Thermostat is showing an error message that says the Rh wire isn't connected, which won't allow you to operate the system from the device or the app, even though you've confirmed that the wires are properly connected to the base. I appreciate you sharing this information. No worries, let's work together to get this resolved. To help with that, I have a few questions for you:

• What type of Nest Thermostat do you have? You can visit the following article to check the model: How to tell which Nest thermostat you have.
• Is this a new installation?
• Are you getting any error codes on your Nest Thermostat display besides the Rh wire error message? If so, what are they exactly?
• Have you experienced any recent power outages?

Any additional details you can provide will be helpful.

Regards,
Jonathan

[joachimhilmeric]

Hi Jonathan!

I have the learning thermostat 3rd generation and the error code is E4. The thermostat has been installed 2 years ago and we did not have any power outages, as per my knowledge.

This happened over night, while I was sleeping!

Now warning before! The thermostat was working before without any issues.

The system is working. However, I cannot adjust the temperature settings and do not have any chance the settings or to adjust the schedule…

[sicsacol]

Hi @joachimhilmeric,

Thanks for your response. I appreciate the time taken to answer the previous questions. Let's try the following steps:

• Turn off ALL breakers controlling your HVAC system at the breaker box and visually check your furnace to confirm all lights are off; if any lights remain on, you must turn off the main power to your entire home. With power OFF, inspect the AC drip pan and drain tubes for standing water or a clog, as a shutdown due to overflow is a common cause of this power error (E4); if a clog is found, you must clear it, but if no clog is present, proceed with the power remaining OFF.
• With the power confirmed OFF, locate the small HVAC fuse, usually on the furnace control board (consult your manual if needed), then remove and inspect the fuse for signs of being burnt or discolored; if it looks damaged, contact a professional for replacement, and if the fuse is good, ensure you securely reattach any furnace panels before proceeding.
• Search near your electric meter or AC unit for a small energy savings box (often marked with red and green lights) installed by a utility company. If you have one, wait 1 or 2 hours for the peak usage time to pass, and then check if the error disappears.

Please let me know how it goes after trying these steps.

Cheers,
Jonathan