How to Fix Nest e73 Error

If you are someone always looking for the next best smart solution for your home, then you might have heard of Google Nest’s smart thermostat product! This is an all-in-one solution to help regulate and maintain the internal temperature of your home using advanced sensors and technology.

The reason why Nest is smart is mostly due to its auto-away mode and this means that it can regulate the temperature even when you are not there based on your previous patterns. It has impressive features and increased sensitivity to the environment.

However, as with all technology, the Google Nest is not immune to its problems! When your Nest will detect a problem, it might send a message or warning to your app or main thermostat. The most common issues are with Wi-Fi connectivity or wiring. Today, we will be looking over the Nest E73 problem and potential ways to fix it.

What is the Nest E73 error?

If you get a message like the E73 error, then you might have a problem with your Nest’s wiring. This will result in it not sending any power to the thermostat and it effectively breaks down. However, this might also be displaying any of the following errors: E3, E4, E23, E24, E73, E74, or E195.

The reason why there are so many wiring issues and errors for Nest is primarily because in extreme temperatures, especially in hot weather, your electronics such as ACs might break down as they are overworked. If this happens your thermostat will pick up on it immediately.

This is why you need to make sure an HVAC professional is looking at your device once every few months for regular maintenance. However, if we want to zoom in on the issue of E73 alone, then this error code is most commonly present when no power is detected going to the RC wire.

This means that your AC outdoor unit has broken down and is no longer functional. In turn, this also shuts down the Nest thermostat. There are a ton of reasons why your Nest device might be displaying an E73 error. We are going to go through some of the main ones and provide you with solutions as well.

While it is true that in many scenarios, simple maintenance and servicing of the AC unit might fix the issue, if the problem persists, you might want to go through with the following checks!

Heres what to do when you get Nest E73 Error:

Solution #1 : Make sure the wiring is good

We have already established that the issue is down to the wiring of your Nest device. So, to make sure that your wiring is not damaged here’s what you should do! Switch the power off on your HVAC system and then remove the thermostat display. Then follow through with these steps:

  • Examine each wire individually as it is placed on your Nest

  • Take off one wire and examine it closely.
  • You need to make sure that the wire has 1cm of copper exposed and it should be straight.

  • You should also check that your wire doesn’t have any signs of corrosion on it.
  • Next, you can add the wire back into the Nest connector and press the connector button firmly down as well.

  • You need to repeat this process with each wire.
  • Finally, you will turn the cooling system back on and make sure it is functional.

If the problem has not been fixed, then move onto the next check!

Solution #2 : Make sure the filter is not clogged

Sometimes, a clogged filter might be the reason why your Nest thermostat’s system is not giving you the required cooling. This might block the airflow especially as it comes from the cooling coils. If your air filter remains clogged, it will freeze over time and your Nest might even shut off.

To fix this, follow these steps:

  • Locate the Nest air filter in the grate in your hallway.
  • Then, make sure that you access it with care and see if it is clogged or dirty.
  • Your Nest needs to be switched off if the issue was frozen coils since they need to thaw and melt out.
  • That’s all of the steps but make sure that your power breaker for the system is shut down because you will be inspecting it closely.

If this wasnt your specific problem, then this next one might help!

Method #3 : Make sure the drip pan is not clogged

Another reason why your Nest device might be displaying the Nest E73 problem might be due to a clog in your drip pan. This can cause the water to back up and since the other elements are shut down, the water might overflow. Again, in this scenario, there is no longer any power being directed to your Nest Thermostat and it causes an E73 power problem.

To fix this, follow these steps:

  • Switch the power off to the HVAC system using the breaker box.
  • Once you have made sure that your Nest system is turned off and each of the breakers is as well, then it is time to look at the fan and furnace.
  • You might also want to look for blinking lights as this might signal that the system is still on.
  • Next, if there is water in your drip pan there might be a clog.
  • Again, as before make sure that in your system there is no corrosion or water damage.
  • If you have it on hand, look at your HVAC user guide or simply Google how to fix a clogged drip line. You might also want to contact a professional to do this for you!

If that still hasn’t solved your problem then you might want to opt for the last and final word of advice we have for you!

Method #4 : Look at the HVAC fuse 

We are now down to our last and final reason why you might be seeing a Nest E73 error on your display. One reason might be due to a fuse burning out. This can cause the system to break down and again, no power is sent to your Nest Thermostat.

Luckily for you, we have all the steps you need to follow listed below:

  • First, as always make sure all the power breakers are off for your HVAC system.
  • Examine the furnace and fan to make sure no lights are still on.
  • Now, coming to the important bit, proceed to check your HVAC fuse. This will be located on the control board but can also be found using the manual your Nest system will come with.
  • Then, you might need to figure out what kind of fuse you need to identify. This is vital and will also be available in the manual. Look for a pink and purple one that has been labeled with the number 3.
  • Finally, you will proceed to take off the fuse and examine it closely. Make sure it is not discolored in any way. If this is the case, then you might have to replace the fuse entirely.

That is it from our side on the Nest E73 problem and how to fix it. While it is true that this is quite technical for some users, it is very basic checking to ensure that your problem can be fixed without the need for a professional!

We have gone over the basics of what the Google Nest Thermostat is all about and have also presented you with methods for its troubleshooting in case problem pops up! We hope that this has been an insightful article for all users who wish to fix their Nest on their own!