Can You Have 2 Thermostats On One Furnace? Need To Know

Rima Chatterjee


To install, wire each thermostat to a zone damper or valve. You can also get a central HVAC control board or an external zone control box. Be careful to mark wires and don’t strip any. 

Can You Have 2 Thermostats On One Furnace

What is a furnace?

A furnace is a heating system that is used to provide heat supplement to the engine.

What is a thermostat?

A thermostat is a temperature control component used to control the temperatures according to the need.

What is a zoned system? 

A zoned system is a furnace system that is used to manage the temperature in various parts of your house separately. 

Can you have 2 thermostats on one furnace?

The furnace is a zoned system and can be paired with two thermostats to set different temperatures for different areas of your house. 

One can get smart thermostats with remote sensors for accurate readings in far-away places. 

To have a zoned system with multiple thermostats controlling different areas of your home, you’ll need a zone control box that works in conjunction with dampers in your HVAC system’s ducts. 

Why do you need multiple thermostats?

Multiple thermostats can be used to control the temperature of various parts of a home or building using one furnace. This is done with multiple thermostats linked to a central HVAC unit with dampers and zoning sensors. These thermostats create different ‘zones’ in your home, each with its own temperature setting.

The top benefit of a zoned system is that it offers tailored comfort. Family members can be satisfied with diverse temperatures in different sections of the house.  If some rooms receive more sunlight or have concrete floors, this solution is even more important. 

It maintains a balance between heating and cooling systems in each zone. Two thermostats on one furnace mean it is a zoned system that helps save energy usage and cost while keeping the house at desired temperatures. 

The thermostat sensors signal to open/close dampers; once the connection is optimized, no two zones require heating/cooling simultaneously, avoiding energy wastage.

How to maximize the efficiency of the zoned system of furnaces using multiple thermostats?

To maximize efficiency with a zoned system and multiple thermostats, do these:

  • Install programmable thermostats that monitor usage and identify patterns/schedules.
  • Place sensors to supply optimal readings in line with climatic variations.
  • Perform regular maintenance of HVAC units and design assessment to ensure zoning functions ideally, without issues like leakages or blockages over time between zones.

These instructions work since they help reduce costs while maintaining efficient heat distribution throughout different zones in your home

Types of thermostats for zoned systems

Zoned systems are awesome for regulating room temperatures. You’ll need more than one thermostat. 

Types of thermostats you can use are 

  • Wired
  • Wireless
  • Programmable
  • Smart

Consider cost, installation ease, and if it works with your HVAC system. Newer HVACs come zoned-in-box.

Can homeowners use smart thermostats with zoned HVAC systems? 

Smart thermostats offer great control over different temperatures in each zone. Plus, they have features like geofencing and voice control.

Check that the thermostat and your heating/cooling equipment work together. Some companies even have multi-zone kits.

Advanced zoning systems use electronic dampers that are controlled by the thermostat or a central controller. 

Installation of the second thermostat and zoning control box

To install a second thermostat and zoning control box, you can have the ability to control temperatures in different areas of your house separately. A smart thermostat can be used to control the zones. 

A step-by-step process for installing a second thermostat

Before installing a second thermostat, turn off the electricity to the heating and cooling systems. 

Then, you can get started with the following steps:

  1. Drill a hole for the wiring between the two thermostats.
  2. Run electrical wiring to connect both thermostats to the zoning control box.
  3. Mount the second thermostat on the desired wall and wire it, according to the manufacturer’s instructions.
  4. Set up each thermostat to regulate specific zones in your home using the zoning control box.

How to wire a zone control box with a damper and zone valve?

Wiring a zone control box with a damper and zone valve might scare you away, but it’s easy to do. 

Zone control boxes improve home energy efficiency by allowing you to regulate temperatures throughout the home. 

Zoning systems have been around since the 1940s, when they were mainly used in commercial buildings. 

Here are four steps:

Step 1Turn off the power to the HVAC system. Take off the cover of the control board to access the wiring terminals. Connect the first thermostat to Zone 1 on the control board with individual thermostat wires.
Step 2Install a second thermostat in another room. Wire it to Zone 2 on the control board. Put different colored wires for each zone. Make sure all wires are connected and insulated.
Step 3Connect the zone valves to their zones on the control board with low voltage wire. Wire the dampers to each of their corresponding zones. Check that each connection is secure and grounded correctly.
Step 4Test both thermostats by adjusting them separately. Make sure both zones function before restoring power to your HVAC system.

How to set temperature settings for zoned systems?

When it comes to setting the temperature for zoned systems, it can be a challenge. To get the perfect climate for each zone, you need to be precise with programming and know the layout of your home. 

Here’s a 4-step guide:

  1. Figure out the location of your thermostats. Each thermostat is linked to a certain zone.
  2. Set the desired temperature range for each zone and program accordingly. You can even create schedules for different days and times.
  3. Install temperature sensors to monitor the climate of each zone. This provides live feedback, so you can adjust settings when needed.
  4. Check up on your thermostats and sensors regularly. Make tweaks based on usage and weather conditions.

Programming options for zoned systems

Keeping your zoned HVAC system is a must for comfy homes. Programming options offer great ways to control temperature, save energy, and better air quality. 

Let’s check out some programming options.

OptionZoning System SettingsFan Control Options
DescriptionIt allows you to set different temperatures for each zone.Set when the fan turns on/off and adjust its speed based on temp changes.
How to Set it UpChoose “Zoning” on your thermostat. Select the temp you want in each zone and save.Select “Fan” in the control menu. Pick desired settings and save them.

How to use remote sensors to control different zones?

Using remote temperature sensors is a great way to control different zones in your home or office. 

These allow you to customize the temperature for each room and guarantee maximum comfort. 

Here’s a guide on how to use them.

Install SensorsStart by installing remote temperature sensors in each room. These will give readings of the temperature variance in each area. Make sure they are compatible with your thermostat models.
Connect with ThermostatConnect the sensors with your thermostat devices using wireless connections like Wi-Fi or Bluetooth. Adjust sensitivity levels for better temperature regulation.
Set PreferencesSet up desired temperatures for individual rooms based on time schedules, occupancy status or seasonal trends. Create programmable heating or cooling profiles.
Monitor & AdjustKeep an eye on temperature readings from remote sensors and make necessary changes via the mobile app. Ensure consistent thermostat settings across all rooms.

Examples of thermostat devices with remote temperature sensors 

Are you trying to cool your home more efficiently? Ecobee and Honeywell offer two great options. 

Consider this:

  • Ecobee: Uses multiple sensors to detect the temperature in different parts of your house. You can also adjust settings from your phone.
  • Honeywell: Similar to Ecobee, but it uses geofencing technology to change the temperature based on your location.
  • Both can be controlled through Amazon Alexa and Google Assistant.
  • These devices can save energy (and money!) by only heating or cooling areas that need it.
  • If you’re not sure which to get, consult an HVAC technician.

An example is a Texan near retirement age who wanted to save energy and stay comfortable during summer. 

They chose an Ecobee 4 with Alexa Voice Service for easy setup, remote thermostat control, and energy savings. They especially liked the ability to manage the temperature in the zones they use the most.

Troubleshooting common problems with zoned systems

To troubleshoot common problems with zoned systems with two thermostats controlling one furnace, refer to the instructions below. 

An HVAC system can be a complex device, and issues can arise from time to time. 

The blower fan not working

The blower fan is a vital part of zoned systems that offer warm or cold air in the house. If it’s not working, troubleshoot by looking at the thermostat settings, circuit breaker, and air filter.

  • Set the thermostat to “auto” instead of “on” mode. This should stop the fan from running continuously.
  • Check the electrical panel of your HVAC equipment for a tripped breaker or a blown fuse.
  • Plus, a blocked or dirty air filter can restrict airflow and make the fan stop working.

Energy Star reports that changing old furnaces with energy-efficient models can save you up to 15% on heating bills each year

Incorrect temperature readings of thermostats in different locations

  • The trouble with the zoned system temperatures may be because of faulty sensors or thermostats in the wrong place.
  • Check that they’re functioning correctly and calibrated. If that doesn’t work, adjust the dampers to balance the airflow.
  • If the issue persists, hire a professional technician. Delay in fixing it could cause higher energy bills and damage to your HVAC system.


Understand the possibility of multiple thermostats. Use zone dampers and temperature sensors to manage airflow and temperature in each room. Popular models like Ecobee or Honeywell have guidelines for wiring multiple thermostats to a single unit.

About the author

Debarghya Roy: A heating systems author, Passionate about energy efficiency and sustainability, Sharing insights and empowering readers through informative blog articles.