Nest Compressor Lockout (Everything you need to know)

Do you want to learn more about Nest compressor lockout or simply looking for a way to save energy costs with your heat pump while at the same time heating your home comfortably? In this article, you should expect to learn about:

Read also: Nest Thermostat Blowing Hot Air on Cool [Solved]

What is Nest Compressor Lockout?

A compressor lockout is simply the temperature below which you want to use auxiliary heating (emergency heat) rather than your heat pump compressor. Compressors lock-out is available on different thermostats and systems but usually, it won’t be explicitly displayed.

For example, if you are using a Nest thermostat for your HVAC system, you won’t be able to explicitly see anything like ‘lockout.’ However, you’ll see something like “Use the heat pump compressor when the outdoor temperature is above”

As the outdoor temperature gets lower, the effectiveness of the heat pump reduces. When your outdoor temperature drops too low, your heat pump won’t be able to keep up with warming your home. That is when your emergency heat will kick in to supplement your heat pump’s heating.

Auxiliary heat is very inefficient but takes a shorter time to warm your home and reach the set temperature quickly.

How Does a Heat Pump Work?

A heat pump works as an air conditioner in the cooling season and as a heater in the heating season. Just like air conditioners, heat pumps use refrigerant to transfer heat between the indoor and the outdoor environment.

Heat pumps are equipped with a reverse valve that switches the direction of the refrigerant, enabling the heat pump to work as a heater in one position and an air conditioner in the other.

If you live in areas with temperatures that drop below 59 degrees in winter, your heat pump will usually have auxiliary heat (emergency heat.)

What Should Compressor Lockout Be Set To?

Heat pumps are an efficient way of cooling your home. They are cheaper than resistive heating, but these come with limitations. Heat pumps are best suited for regions with mild temperatures. That is in regions where the temperature doesn’t fall below 30 degrees.

The government states that the control for lockout temperature shall be at maximum 40 degrees and 32 degrees or less at final inspection.

Heat pumps are designed to work effectively where outdoor temperatures are 30 degrees or above. That explains why heat pups are backed by auxiliary heat (emergency heat.) So that, when outdoor temperatures fall below 30 degrees, the auxiliary heat will kick into action.

What is Nest Auxiliary Heat Lockout?

Auxiliary heat lockout for the Nest or any other thermostat is the temperature above which you want your system to use the compressor to heat your home rather than auxiliary heat. Auxiliary heat lockout helps homeowners to save on heating costs.

Heat pumps utilize the technology of using a refrigerant to extract heat from the outside air and transfer it into your home. However, the aux heating cost be 2-5 times more than heat pumps.

Also read: Nest Thermostat Not Turning on AC Compressor [Solved]

How Do I Turn on The Auxiliary Heat on My Nest Thermostat?

To turn on Aux heat on your thermostat, you need to be sure that your system is equipped with supplementary heating (aux heat.) You can verify this by checking if there is an E terminal on your thermostat and if there is a wire connecting to it.

You can turn on AUX heat from your app or directly on your thermostat. To turn on AUX heat from your home app do this:

  1. Go on the google home app and select thermostat
  2. On the thermostat select the settings(gear) icon and then
  3. Select emergency heat and
  4. Use the switch button to turn it on or off

To turn on AUX heat from your thermostat, do the following:

  1. Go to settings and 
  2. Pick the emergency heat settings
  3. Select continue then ‘yes’ to continue
  4. If emergency heat is already activated, select ‘leave on’ to leave it on or ‘turn off’ to deactivate it.


Why is My Nest Aux Heat not Working?

If you are dealing with aux heat not working on a Nest thermostat, the first thing you want to do is verify that your system supports aux heat. If you don’t know whether your heating system has aux heat, you can verify this by:

  1. Checking if there is a wire connected to the W2/AUX terminal. If there is no wire in there, then your system is not configured to use Auxiliary heating.
  2. Checking your manual or search for model number of your heating system on your manufacturer’s website. You should be able to see information about whether your system supports Aux heating or not.

However, if you are sure that your system has secondary heating, but aux heat is not working, then your thermostat wires could be loose or not connected properly.

Pull off your nest thermostat from the wall and double-check your thermostat wiring. If there are no problems with your thermostat wiring, there is a good chance that your thermostat model wasn’t correctly set up.

Depending on your Nest thermostat model, follow these steps to correctly set up your thermostat. Or do a system reset.

Final Thought

Now that you know what nest compressor lockout is, we hope you’ll be able to heat your home more comfortably while at the same time being careful on saving some energy costs. The same applies to nest auxiliary heat lockout, it can help you save on electricity bills, especially if used together with heat pump balancing. Thanks for reading.

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