Why does Nest say aux heat? When the weather outside gets colder than your lockout temperature, your thermostat will start using AUX heat. If you have a heat pump with AUX heat, your Nest thermostat will use Heat Pump Balance to determine your lockout temperature automatically. Click to see full answer.
Does aux heat work with Nest Thermostat?
AUX heat can also start if the pump can’t handle the outside heat on cold winter nights. If the walls of your home are too cold and your heat pump is not powerful enough, AUX heat may be needed in order to make up the degrees. You don’t have to connect your Nest thermostat to your Wi-Fi network.
What is aux heat and how does it work?
Your system can use AUX heat to help keep you comfortable in harsh weather or to help change the temperature in your home quickly. Heat pumps are very efficient compared to most other heating systems, but they take longer to heat your home the colder it gets outside.
Why does my aux heat keep turning on?
AUX heat can turn on when the heat pump alone isn't working fast enough, it's too cold outside, or your heat pump needs to defrost. Note: Normal programmable thermostats have one way to control AUX heat: the AUX lockout temperature. If it gets colder outside than the set lockout temperature, your heat pump will use AUX heat.
What happens to aux heat when ice melts?
AUX heat turns on to keep you warm. Once the ice on the heat pump has mostly melted, the heat pump goes back to normal and AUX heat turns off. Heat pumps have 2 forms of AUX heat:
How do I stop nest from using auxiliary heat?
Using the Built-in Nest Thermostat Settings Then, select Settings. Go to Nest Sense. Select Heat Pump Balance. From here, choose between Max Savings and Off.Oct 10, 2021
Why does my heat say aux?
“Aux” is short for auxiliary heat. If a heat pump is having a difficult time coming up to a certain temperature quickly due to extremely cold outdoor temperatures, the “aux heat” indicator means that a secondary heat source (generally gas or electric) has been deployed.Feb 25, 2020
Is it bad to run AUX heat?
Is AUX heat bad? The short answer is no. In fact, aux heat is a critical mechanism that keeps your heat pump properly running when the outdoor temperature drops. Since this type of unit doesn't work the same as a furnace, it can get cold.
Why does my Nest thermostat adjust the temperature?
This is supposedly because AUX heat will be needed to warm up your home when you get up in the morning. But the Nest thermostat learns how quickly your home heats and cools, so it can adjust the temperature while you sleep to minimize AUX heat use to warm up your home in the morning.
What is an auxiliary heat pump?
Auxiliary (AUX) heat is a second source of heat that comes with some heat pump systems. Heat pumps are the main source of heat most of the time, but they aren't efficient when it's very cold outside. Your system can use AUX heat to help keep you comfortable in harsh weather or to help change the temperature in your home quickly.
What happens if the heat pump is off?
Your heat may still turn on early, and your lockout temperature will be between the temperature used for Max Savings and Max Comfort. Off: If Heat Pump Balance is off, your thermostat will use your AUX heat based on a lockout temperature that you set.
What is a heat pump balance?
Heat Pump Balance lets you select a level of comfort and energy savings that you like: more comfort, more savings, or a balance between the two. You can change this option any time in the Nest Sense menu. No matter which setting you choose, Heat Pump Balance monitors how efficiently your heat pump is working, the current weather, ...
What happens if you don't have a wire in the thermostat?
Important: Do not touch the wires in your thermostat while you check them. Pull off your thermostat’s display. If there’s no wire in the O/B connector, your system is not configured as a heat pump. If you don’t have a wire in the W2/AUX connector, you don’t have AUX heat. Heat Pump Balance controls AUX heat.
How long before a heat pump can you turn on?
Heat Pump Balance can turn on the heat up to 5 hours before a scheduled temperature, if necessary. How Heat Pump Balance works while you sleep. Some people will tell you that setting low nighttime temperatures if you have a heat pump will waste energy.
Do you need to set a lockout temperature on a Nest thermostat?
So you won't need to set a lockout temperature yourself, your Nest thermostat will set one for you. If you have a dual fuel system, a type of system with a heat pump outside and a separate heater installed inside your home, you won't be able to use Heat Pump Balance.
What does AUX mean on a thermostat?
Turning your thermostat to “heat” came with an unexpected “AUX” function appearing. What does it mean? The “ AUX Heat ” mode is usually an indicator that it’s freezing outside, and your is heat pump is using a secondary backup heat source – your auxiliary heat—to keep your home at your set temperature. If the “AUX” signal shows all the time ...
Why does my heat pump switch to AUX?
On super chilly nights in Minnesota, the heat pump switches to AUX heat because there’s not enough heat outside to keep your home at the desired temperature. 2) When the heat pump ices over.
How does a heat pump defrost?
When it gets to freezing temperatures, ice can build up on your outdoor unit. The heat pump defrosts by going from “heat” mode to “air conditioning” mode. In other words, it uses the warm air in your home to melt the ice. But, cool air is now being pumped into your home through your vents.
Try a Restart
Before taking any drastic measures, it’s worth restarting your Nest to see if the problem is solved. Restart Nest by pressing and holding the ring on the thermostat until the screen goes blank. This should take about 10 seconds. Let go of the ring and keep it off for a minute or two. To turn Nest back on, press and release the ring.
Wiring Check
Incorrect wiring can lead to a whole host of problems. Usually, you’ll notice a wiring issue early after installation, especially if you did it yourself. But sometimes, issues can crop up later for different reasons. Check the wiring with the following steps:
HVAC System Maintenance
Assuming all is well with your wiring, the next place to check is with your HVAC system. In particular, Nest users have reported a dirty flame sensor as the cause of Nest’s confusion. It could be that your system simply needs maintenance.
Insufficient Power to Nest
Insufficient power to your Nest can lead to a laundry list of issues. If you’ve tried all the above troubleshooting advice to no avail, you can see if additional power is the solution.
Related Questions
Many HVAC systems employ a built-in delay as a safety feature. If a system turns off and on frequently, the lifespan is shortened. The delay, which should only be a few minutes, is there to prevent excessive wear on the unit. So really, this delay is coming from your HVAC system, not Nest.
Summing It Up
If your Nest says it’s heating when it’s not, there could be a wiring issue or a problem with your HVAC system. Many users reported a dirty flame sensor is the culprit. It’s also possible your Nest isn’t receiving enough power.
