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Why Does My Nest Thermostat Say Delayed?

The Nest thermostat is a handy smart home device that makes it super easy to monitor your energy consumption and maintain a comfortable temperature within your home.

Like any tech device, it can be challenging to pinpoint the source of a particular problem or issue on a Nest thermostat, which makes resolving it seem daunting or confusing.

One such problem is the ‘Delayed’ notification which can appear on a Nest thermostat from time to time.

Thankfully, this isn’t a serious issue, and we’ll explain the delay message in-depth and how you can fix it in this article.

Your Nest thermostat may show a ‘Delayed’ notification when first installed or after rebooting. It can also appear due to a low HVAC power supply. In this case, the lack of power drains the device’s rechargeable lithium-ion battery too quickly, causing a delay to its operating functions.

Read on to learn more about diagnosing the delay notification issue on your Nest thermostat and the various ways you can resolve the problem.

Why Does My Nest Thermostat Say Delayed?

The ‘Delayed’ message on Nest Thermostats is a common issue that arises for many people.

In some cases, the delayed message results from a power shortage or an underpowered thermostat which you can fix via the device’s wiring system.

A common misconception is that a Nest thermostat gets its power from mains electricity, but that isn’t the case. The devices are powered by a rechargeable lithium-ion battery, which receives power from the HVAC system.

The battery’s power can sometimes drain too quickly if you use your heating system infrequently or if there is an issue that restricts power from reaching the thermostat. When this happens, the thermostat’s power is at too low a level, temporarily delaying its ability to function.

If this situation were to arise, the HVAC system wouldn’t operate efficiently. It will unpredictably turn off and on, which could cause costly damage to the system in the long run and is, therefore, something you should try to avoid.

The delayed message isn’t always a result of a power shortage or underpowered thermostat, though, and we’ll cover some of the other potential causes in the next section.

Why Does My Nest Say ‘In 2 Hours’?

A common misconception is that the duration shown on a Nest thermostat, for example, the ‘2+ hour’ message shown below, is effectively a delay notification, but this isn’t the case.

why does my nest thermostat say delayed article image - image showing the heating or cooling duration shown on a nest thermostat


Where a timescale appears on the screen without the word ‘Delayed,’ the Nest thermostat is simply indicating the time it will take to heat or cool the space to your selected temperature.

We should mention that the time won’t necessarily be two hours for your thermostat. Instead, it depends on how long it’ll take to heat or cool the space, with more considerable increases or decreases in temperature taking more time.

If your Nest thermostat’s digital reader specifically includes the word ‘Delayed,’ though, it means your heating and cooling functions have been put on hold.

There are three main reasons why this happens:

  1. Your Nest Thermostat has only recently been installed.
  2. You have recently rebooted your system.
  3. There is an issue with the thermostat’s wiring circuit.

Let’s take a closer look at each of these, and cover how to fix the issue should you need to:

Your Nest Thermostat Has Been Recently Installed

A newly installed Nest thermostat won’t know how long it takes for your home to heat up or cool down, which is why it will need some time to ‘settle in’ to get to know your home before it can perform optimally.

If you have recently installed your Nest Thermostat and it starts showing the message ‘In 2 Hours’, you need to give it some time to learn enough about your home before it can provide you with a more exact estimate.

You Recently Rebooted Your System

A total system reboot will remove all the data saved in your Nest thermostat, so it will essentially have to re-learn your home again as if it was a newly installed device.

As above, give the thermostat sufficient time to learn more about its surroundings, and the delay message should disappear.

There Is an Issue With the Wiring Circuit

A Nest thermostat relies on a power supply from your home’s HVAC system to operate.

If there is a missing wire or incomplete circuit between the HVAC and Nest thermostat, this could be another reason why your device is displaying the delayed notification.

To check whether or not your device’s circuit is complete, open the settings on your Nest and scroll to ‘Equipment’.

You should see a wire for the following: Y1 for the cooling system, G for the fan, W1 for heat, RH for power, and C for the common wire.

If the C wire is missing from the display, this means you will need to attach the common wire to complete the circuit.

What Is the Common Wire?

The C wire, or ‘common wire’ provides a constant flow of 24 volts AC power to the Nest Thermostat.

When the R wires are connected, the C wire completes the circuit between the HVAC and smart thermostat, which is what provides a continuous stream of power that keeps the Nest thermostat operating 24/7.

What Color Is the C Wire?

In most HVAC systems, the C wire is either blue or black. The R wires are red, the G wire for the fan is green, the W wire for heat is white, and the Y wire for the air conditioner is yellow.

How Do I Know if My Nest Thermostat Has a C Wire?

Just because you can’t see a C wire connected to your Nest Thermostat’s terminal doesn’t necessarily mean it doesn’t have one.

In some cases, the installer may run the C wire from the HVAC board without connecting it to the device terminal. If so, you should be able to find a blue or black wire tucked behind the thermostat – this is the C wire.

If you have checked behind the thermostat and the terminal at the HVAC board and can’t find the wire, the installer or previous occupant likely never installed the C wire.

If this is the case, you could get a professional to install the C wire for you or connect it yourself. We have included some instructions on the process of installing a C wire later on in the article.

Alternatively, you could purchase a C wire adapter and attach it to the thermostat for a quick and inexpensive fix.

What Is a C Wire Adapter?

If your Nest Thermostat is missing the C wire, one option is to install a C wire adapter.

This simple device can provide a constant source of power to the Nest Thermostat by drawing power from the mains electricity supply rather than the HVAC system.

How Do I Install a C Wire Adapter?

Installing a C wire adapter is a quick and easy process that doesn’t always require a professional electrician.

Having said that, if you’re unsure of the process or have any reservations, we’d strongly recommend getting a professional electrician to complete the steps below. It’s better to be safe than sorry, as they say.

The first step is to remove the front of your Nest Thermostat to reveal the wiring terminals.

The adapter has two wires attached to it – connect one to the Power (RH) terminal and the other to the Common (C) terminal.

You will then need to connect the adapter plug to the mains electricity by plugging it into a nearby wall socket.

Although this is a quick and simple fix to the problem, it does mean you will be able to see the wire coming out of the thermostat device and going into the wall outlet, which can look untidy.

How to Fix the Nest Thermostat Delay

As we’ve already established, the ‘Delay’ notification results from an insufficient power supply to the Nest thermostat.

While some older thermostat models allow you to replace the battery when this happens, the Nest thermostat has a lithium-ion battery that you cannot replace easily.

Therefore, when there isn’t enough power reaching the Nest device, it will usually be down to a wiring issue or a missing C wire.

If your Nest Thermostat is currently displaying the ‘Delay’ notification, the following steps will help you fix the issue:

Charge the Battery

In situations where the Nest thermostat’s battery is drained of power, and there’s an insufficient power supply coming from the HVAC system, you could try charging the battery manually to get it working again.

To do this, remove the front of the device on the wall to reveal the micro-USB port.

Go ahead and connect a compatible charger to the device and give it some time to recharge the battery.

Once you have left it for some time, replace the front of the Nest Thermostat, and you should notice the ‘Delay’ notification is no longer showing.

Although this is a quick fix, it’s not a permanent solution to the ‘Delay’ issue because you will have to recharge the battery regularly if it isn’t getting enough power from the HVAC system.


Check if the Nest Thermostat Is Newly Installed

As mentioned above, newly installed Nest thermostats typically take a bit of time to learn how to heat and cool your house efficiently.

If your device is new and displays the message ‘Delayed for 2 Hours’, or some other timescale, there’s no need to panic. Give the device a bit of time to settle in, and it will soon be operating as normal.

Similarly, you’ll also see the delay notification if you have recently reset your Nest thermostat.

The delay occurs because the device will have lost all the saved data it has learned about your home, so you’ll need to treat it like a new device and wait a couple of days for it to get back on track again.


Check for Software Updates

Like most smart devices, Nest thermostats rely on regular software updates to ensure they run as smoothly as possible.

If your device is displaying the ‘Delay’ notification, it could be because it is running an update and unable to operate its regular functions.

Any ‘Delay’ notification is entirely normal here, so don’t worry if you notice this happening with your device. Leave the device for a bit of time to complete the updates, and it should start working normally again.


Check if a C Wire Is Connected

As mentioned earlier in the article, the C wire is an essential component within the Nest Thermostat’s operating system because it supplies a constant power source to the device.

To find out if the C wire has been hooked up to your Nest thermostat, open the settings menu on your device and scroll to the equipment menu. Here, you will see which wires are connected to the device and which wires are missing.

How to Install a C Wire

If you have checked your Nest Thermostat’s settings and have discovered there is no C wire installed, we will guide you through the process of getting your device up and running again.

Depending on your circumstances and experience, there are several options from which you can choose.

We’ve already discussed how installing a C wire adapter is a quick but not necessarily permanent fix to the ‘Delay’ issue, but here are some other solutions to choose from:

  1. Install a new C wire from the HVAC system to the thermostat terminal.
  2. Hire a professional electrician to install a C wire.
  3. Use the Fan (G) wire instead of the C wire.

Let’s look at each one in more detail:

Option 1: Install a New C Wire Yourself

If you feel confident enough to run the wiring and hook it up yourself, this will be a cost-effective and logical option for you.

Having said that, as mentioned above, if you’re unsure of the process or have any reservations, we’d strongly recommend getting a professional electrician to complete the steps below.

The complexity of this option will also depend on how close your Nest thermostat is to your HVAC system.

For example, if you live in a 3-story house and your HVAC is in the attic, but your thermostat is on the first floor next to the front door, you would most likely have to run the wiring down through the entirety of your home, which is a big task.

If you have considered these factors and are happy to proceed with taking on the installation process yourself, here is a rough overview of the steps involved:


Establish the Wiring Route

Firstly, work out the route the wire will need to take to get it from the HVAC system to the Nest thermostat.

It may be a simple case of drilling one hole through the wall, or it could be a slightly more complicated route that you need to map out through your home.


Connect the C Wire to the Nest Thermostat

Pull the wire into the thermostat and connect it to the corresponding terminal on the device.

Ensure that it is securely connected and there are no tangles or kinks in the wire. You will then need to pull it through the device and work it through the walls until the other end reaches the HVAC system.

A set of wire rods can help you feed the wire through awkward and hard-to-reach spots.


Connect the C Wire to the HVAC System

Once the wire has been pulled through your home and has reached the HVAC equipment, you will need to connect it to the correct terminal to complete the circuit.

Firstly, remove the cover and turn off the HVAC system by unplugging it or pressing the switch at the circuit breaker.

Locate the thermostat terminals labeled R, W, Y, G, and C.

Connect the C wire you have pulled through from the Nest Thermostat to the C terminal on the HVAC board.

Switch the HVAC system back on at the mains and replace the front cover.


Configure the Settings on the Nest Thermostat

Finally, return to the Nest Thermostat device and follow the setup instructions to confirm the C wire is installed and connected correctly.

If you open your ‘Equipment’ menu on your device, it should show that the C wire has been successfully connected.

With the C wire installed, your Nest thermostat should no longer display the ‘Delay’ notification because it will be receiving a constant flow of power from the HVAC system.

Option 2: Hire a Professional to Install a C Wire

If the instructions from the first option have gone over your head, or you don’t feel confident pulling wires through your home, you could always hire a professional electrician to take on the task for you.

At the risk of repeating ourselves, if you don’t feel confident, we’d strongly recommend getting professional help to prevent damaging your Nest thermostat, your home, or worst of all, yourself.

Option 3: Use the Fan (G) Wire Instead of the C Wire

The G wire is the green wire that controls the fan, and you can use it to trick your thermostat into thinking you have installed a C wire.

All you will need to do is turn off the HVAC system and remove the front panel from your thermostat device, take out the G wire from the G terminal and reconnect it to the C terminal.

You will then need to go back to your HVAC system terminals and do the same there. Turn the system on again and return to your Nest thermostat to complete the setup in the settings menu.

If you opt for this solution, you should note that you will no longer be able to use your fan independently for heating or cooling your home. Hence, it’s important to consider the implications of this before proceeding.

In Summary

The delayed notification on a Nest thermostat is a relatively common issue, and there are several ways to resolve it, as outlined in this article.

In some circumstances, you could be seeing the delayed message because you have recently installed or rebooted your Nest thermostat, and it needs some time to get up to speed with heating and cooling your home.

In most cases, the delayed notification will be down to a lack of constant power supply, usually caused by a missing or unconnected C wire.

We hope this article has provided the guidance you needed to find a suitable resolution for your Nest thermostat device. If not, we’d recommend contacting Google Nest support which you can do here.

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Author: Tamsin Bright
Writer, ToolCrowd
Tamsin Bright regularly writes about architecture and home design topics and is the editor for the Smart Home and Home Tech sections of ToolCrowd. Tamsin holds a bachelor’s degree in Architecture and loves nothing more than helping people see the potential in their homes and making their lives easier through great design. When she’s not writing for ToolCrowd, you can find Tamsin indulging her passions for graphic design, cooking, gardening, and all things tech. Contact Tamsinarrow_right_alt