Nest Thermostat Says “Delayed” or “Starts in”: What It Means and How to Fix It

The Short Answer

A Nest thermostat shows Delayed or Starts in with a countdown, for example “Heating is delayed for 2:30 mins”, when it is holding the system off for a short time. Google lists this message among the signs that a Nest thermostat has a power issue, and says it often appears on the screen when power is the cause.

If you see it once and the system then starts, there is nothing to fix. If it appears often, or with the other signs below, follow Google’s steps in order. Most end at the same place: a C wire or the Nest Power Connector.

Other Signs That Point to Power

Google groups Delayed with these symptoms. The more of them you recognise, the more likely power is the cause:

• The battery drains faster than it used to, or the display will not turn on.
• The thermostat occasionally disconnects from Wi-Fi.
• Heating or cooling turns on or off unexpectedly, stays on, or cycles on and off repeatedly.
• The system makes chattering, stuttering, clicking or thumping noises.
• The fan is always running, will not turn on, or turns on and off repeatedly.
• Motion sensing is disabled.
• An error code: E1, E297, N260, N261, N410 or N411.

For the battery and power error codes on their own, see Nest low battery and Nest no power to Rh wire.

Google’s Fix, Step by Step

These steps follow Google’s guide to strange heating or cooling behaviour, which is where it sends you for a Delayed message.

1. Check the energy history. In the Google Home app, open the thermostat and tap the energy dashboard; in the Nest app, tap History. It shows when the system ran and why a change happened.
2. Make sure every wire is fully inserted. Turn the system power off at the breaker first. Pull off the display and check that each connector button is pressed down. Google notes that the thermostat will not know a wire is there if the button is not down. Strip and straighten a wire end if it will not seat.
3. Put the old thermostat back. This is Google’s own test. If the old thermostat runs the system normally, the issue is Nest compatibility or power. If the old one has the same problem, the system needs maintenance, not the thermostat.
4. Check compatibility. Most 24 V systems work with Nest thermostats, but some need a C wire or the Nest Power Connector. Google’s checker is at g.co/nest/works.
5. Fix or connect a C wire. If there is already a wire in the C connector, check it is also on the C terminal of the system’s control board. If there is no C wire, look for a spare wire in the bundle that can be connected to C at both ends.
6. No spare wire? Use the Nest Power Connector. Google describes it as a simpler alternative to a C wire that also costs less.
7. Or have a pro do it. A local HVAC professional can install the Power Connector, use a spare wire or run a new one, and check for an underlying system problem.

Google also says to suspect the system, not the thermostat, when the screen changes colour (blue for cooling, orange for heating) but nothing turns on, or when the problem goes away after a power restart and then returns.

The Part for a Missing C Wire

The Nest Power Connector gives a Nest thermostat steady power on systems that cannot supply enough on their own. It works with the Nest Thermostat, Nest Thermostat E and the Nest Learning Thermostat (3rd and 4th gen), on 24 VAC systems only; it is not for millivolt or high-voltage systems. It installs at the furnace or air handler (or at the zone controller on a zoned system), not at the thermostat.

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Normal or Not: A Quick Table

When to Call a Technician

• The old thermostat shows the same problem.
• There is no C terminal on the control board, or you are not comfortable working inside the furnace or air handler. Google recommends a professional in both cases.
• The wiring is correct, a C wire or Power Connector is fitted, and the delays continue.

Frequently Asked Questions

What does Delayed mean on a Nest thermostat?

The thermostat is holding the system off for a short time and shows a countdown, such as "Heating is delayed for 2:30 mins". Google lists a Delayed or Starts in message among the signs of a power issue.

Why does my Nest keep saying Delayed?

Repeated Delayed messages are one of Google's listed signs that the thermostat is not getting enough power. The usual fix is to connect a C wire or install the Nest Power Connector.

How do I fix Delayed on a Nest thermostat?

Follow Google's order: check the energy history, make sure every wire is fully inserted, test with the old thermostat, check compatibility, then connect a C wire or install the Nest Power Connector.

Does a Nest thermostat need a C wire?

Not always. Google says most 24 V systems work with Nest thermostats, but some need a C wire or the Nest Power Connector. Its compatibility checker at g.co/nest/works tells you which.

Which thermostats does the Nest Power Connector work with?

The Nest Thermostat, Nest Thermostat E and the Nest Learning Thermostat 3rd and 4th gen, on 24 VAC systems. For 1st and 2nd gen Learning Thermostats, Google says to consult a Nest Pro.

Related Guides

• Nest thermostat low battery — when the battery will not hold charge
• Nest “No power to Rh wire” — the power error codes explained
• Nest thermostat offline — when it drops off Wi-Fi
• Smart thermostat troubleshooting — every fix guide by symptom

Sources

• Google Nest Help: Troubleshoot strange heating or cooling behavior
• Google Nest Help: signs of low power
• Google Nest Help: Nest Power Connector compatibility