Honeywell Thermostat Blowing Cold Air On Heat Setting- [Fixed]

A functional thermostat is the unsung hero of your home’s heating system, ensuring comfort and warmth during the chilly seasons. However, there’s nothing more frustrating than expecting cozy heat and getting an unexpected blast of cold air. 

If you own a Honeywell thermostat and find yourself in this situation, don’t worry – you’re not alone. 

In this guide, we’ll delve into the troubleshooting process to help you understand why your honeywell thermostat blowing cold air on heat setting and provide practical solutions to get your heating system back on track. 

Let’s dive in and explore the common causes and steps to rectify this issue, so you can enjoy a comfortably warm home once again.

How Does Your Honeywell Thermostat Works?

To effectively troubleshoot the issue of your Honeywell thermostat blowing cold air when set to heat mode, it’s crucial to have a solid grasp of how these thermostats work. 

Honeywell thermostats are renowned for their user-friendly design and advanced features, making them a popular choice for homeowners. Here’s a brief overview:

Temperature Control

The primary function of your Honeywell thermostat is to control the temperature in your home. 

You can set your desired temperature, and the thermostat’s internal sensors work to maintain it.

Heating and Cooling Modes

Honeywell thermostats typically offer both heating and cooling modes. In this context, we’re focusing on the heat mode, where you expect warm air when the temperature drops.

Programmable Features

Many Honeywell thermostats come with programmable features, allowing you to set schedules for temperature changes throughout the day to save energy.

Settings and Interface

Honeywell thermostats have user-friendly interfaces, often featuring digital displays and intuitive controls for adjusting settings.

8 Causes for Honeywell Thermostat Blowing Cold Air on Heat Setting

When your Honeywell thermostat is blowing cold air instead of providing the warmth you expect in heat mode, several underlying issues could be at play. 

It’s essential to identify the potential causes before attempting any troubleshooting. Here are 8 common factors to consider:

1. Incorrect Temperature Setting

Double-check that the thermostat is set to the desired temperature in heat mode. A simple adjustment may solve the problem.

2. Power Supply Issues

In some cases, power interruptions or dead batteries can affect thermostat operation. Ensure the thermostat has a stable power source.

3. Thermostat Wiring

Faulty or disconnected thermostat wiring can disrupt communication between the thermostat and your heating system. Inspect the wiring for any visible issues.

4. System Compatibility

Ensure that your Honeywell thermostat is compatible with your heating system. Incompatibility can lead to improper functioning.

5. Dirty or Clogged Filter

A clogged air filter can restrict airflow, causing your heating system to work inefficiently. Regularly changing or cleaning filters can alleviate this issue.

6. Heating System Problem

The issue may not be with the thermostat itself but with the heating system. Problems like a malfunctioning furnace or heat pump can result in cold air blowing.

7. Sensor Calibration

Some thermostats use internal temperature sensors. Calibration issues or sensor malfunctions can lead to incorrect temperature readings.

8. Software or Firmware Update

Ensure your thermostat’s software or firmware is up-to-date. Manufacturers often release updates to address performance issues.

Step by Step Troubleshooting Guide Of Honeywell thermostat blowing cold air when set to heat mode

We already explored the possible causes of your Honeywell thermostat blowing cold air during the heat setting, Now let’s proceed with a comprehensive step-by-step troubleshooting guide to help you pinpoint and resolve the issue:

1. Check Temperature Setting

   – Verify that your thermostat is set to the desired temperature in heat mode. Make any necessary adjustments.

2. Inspect Power Supply

   – Ensure the thermostat has a stable power supply. Replace batteries if needed or check for any power interruptions.

3. Examine Thermostat Wiring

   – Carefully inspect the thermostat wiring for loose or disconnected wires. Reconnect any wires that may have come loose.

4. Confirm System Compatibility

   – Review your thermostat’s compatibility with your heating system. Refer to the thermostat’s manual or the manufacturer’s website for guidance.

5. Address Filter Issues

   – If you haven’t done so recently, check and clean or replace the air filter in your heating system. A clogged filter can impede airflow.

6. Heating System Inspection

   – If the above steps don’t resolve the issue, consider checking your heating system for malfunctions. This may involve inspecting your furnace, heat pump, or other components.

7. Sensor Calibration

   – If your thermostat uses internal sensors, ensure they are calibrated correctly. Refer to the thermostat’s manual for calibration instructions.

8. Software/Firmware Updates

   – Check if there are any available software or firmware updates for your Honeywell thermostat. Updating it could potentially address performance issues.

9. Reset the Thermostat

   – As a last resort, you can try resetting your thermostat to its default settings. Refer to your thermostat’s manual for instructions on how to do this.

10. Professional Assistance

    – If you’ve followed these troubleshooting steps and still encounter the problem, it may be time to seek assistance from a professional HVAC technician who can diagnose and repair any issues with your heating system or thermostat.

Professional Help vs DIY in Honeywell Thermostat Fixing

When facing the frustrating issue of your honeywell thermostat blowing cold air on heat setting, you might wonder whether to tackle the problem yourself or seek professional assistance. 

Here’s a breakdown of when it makes sense to go the DIY route and when it’s best to call in a professional HVAC technician:

DIY Troubleshooting

1. Simple Fixes

If the problem appears to be a minor issue such as incorrect thermostat settings or a dead battery, you can attempt to resolve it yourself. Follow the troubleshooting steps outlined earlier in this guide.

2. Filter Replacement

Changing or cleaning air filters is a straightforward DIY task that can improve heating system performance. It’s something you can do regularly to prevent issues.

3. Software/Firmware Updates

If your thermostat has the capability for updates, you can typically handle this yourself by following the manufacturer’s instructions.

4. Sensor Calibration

If your thermostat uses internal sensors and provides calibration instructions in the manual, you can attempt this adjustment yourself.

When to Seek Professional Assistance?

1. Complex Issues

If you’ve followed the troubleshooting steps and the problem persists, or if you suspect a more significant issue with your heating system, it’s advisable to consult a professional HVAC technician.

2. Electrical or Wiring Problems

Any issues related to electrical wiring or the connection between your thermostat and heating system should be handled by a qualified technician to ensure safety.

3. System Repair

If the problem lies within your heating system itself, such as a malfunctioning furnace or heat pump, it’s crucial to have a professional technician diagnose and repair it.

4. Compatibility Concerns

If you’re uncertain about the compatibility of your thermostat with your heating system, seeking expert advice can prevent further complications.

5. Safety First

When in doubt or if you’re uncomfortable with any DIY steps, prioritize safety and consult a professional. Electrical components and gas systems can pose risks if mishandled.

10 Tips for Preventing Future Issues in Honeywell Thermostat

Once you’ve successfully resolved the problem of your Honeywell thermostat blowing cold air on the heat mode, it’s essential to take proactive measures to prevent similar issues from arising in the future. 

Here are some valuable tips to help you maintain your thermostat and heating system for consistent and reliable performance:

1. Regular Maintenance

Establish a routine maintenance schedule for your heating system. 

This includes cleaning or replacing air filters, inspecting ducts, and ensuring that vents and registers are unobstructed.

2. Thermostat Check-Up

Periodically check your thermostat’s settings to ensure they align with your comfort preferences and the season. Adjust the schedule as needed.

3. Battery Replacement

If your thermostat uses batteries, replace them as recommended by the manufacturer or when you notice low battery indicators. Fresh batteries are essential for reliable operation.

4. Software Updates

Keep your thermostat’s software or firmware up-to-date by installing any available updates. These updates often include bug fixes and improvements.

5. Temperature Calibration

If your thermostat has internal sensors that require calibration, revisit this process periodically to maintain accuracy.

6. Professional Inspection

Schedule an annual or bi-annual inspection by a qualified HVAC technician. They can identify and address any potential issues before they become major problems.

7. Smart Thermostat Feature

If you have a smart thermostat, take advantage of its features such as remote control and energy-saving settings. These can help optimize your heating system’s efficiency.

8. Weatherproofing

Ensure your home is well-insulated and weatherproofed to reduce the strain on your heating system. Proper insulation helps maintain a consistent indoor temperature.

9. Learn Your System

Familiarize yourself with your heating system’s components and how they work. This knowledge can help you detect early signs of trouble.

10. Emergency Plan

In case of an unexpected heating system failure during cold weather, have a backup plan to keep warm, such as portable heaters or blankets.

Honeywell Thermostat Caring Tips for Optimal Performance

Regular Cleaning

Dust and debris can accumulate on the thermostat’s display and sensors, affecting its accuracy and responsiveness. 

Use a soft, lint-free cloth to gently wipe the screen and surrounding areas. Avoid using abrasive or chemical cleaners, as they can damage the device.

Check Batteries

If your thermostat uses batteries, it’s essential to check them regularly. Low or dead batteries can lead to thermostat malfunctions. 

Replace the batteries as needed, typically once a year, or as indicated by the low battery warning.


Calibrating your thermostat ensures accurate temperature readings. To do this, use a separate, accurate thermometer to compare the displayed temperature on your thermostat. 

If there’s a significant difference, consult the user manual or contact Honeywell support for calibration instructions.

Keep Vents and Registers Clear

To allow your thermostat to function optimally, ensure that air vents and registers in your home are not obstructed by furniture or other objects. 

Proper airflow helps maintain consistent temperature control.

Firmware Updates

Honeywell may release firmware updates for your thermostat to improve performance and add new features. 

Check for updates periodically and follow the manufacturer’s instructions for installing them.

Seasonal Adjustments

Adjust your thermostat’s settings seasonally to maximize energy efficiency. Lower the temperature in the winter when you’re away and raise it in the summer.

Consider using programmable or smart thermostats for more precise control.

Protect from Extreme Conditions

Extreme heat, cold, or humidity can affect your thermostat’s performance. 

Install your thermostat away from direct sunlight, drafts, or moisture-prone areas. This helps maintain its accuracy and prolong its lifespan.

Professional Maintenance

If you encounter persistent issues or suspect a malfunction, it’s advisable to seek professional help. 

Certified HVAC technicians can diagnose and repair any underlying problems with your thermostat or HVAC system.

FAQs (Frequently Asked Questions)

Can a thermostat software update resolve the issue of cold air blowing during the heat setting?

Software or firmware updates can address certain performance issues with your thermostat. Check the manufacturer’s website or user manual for instructions on how to update your thermostat’s software.

Are there any energy-saving tips for using my Honeywell thermostat?

Yes, Honeywell thermostats often come with energy-saving features. Consider programming your thermostat to lower the temperature when you’re away and raise it when you’re home. This can help reduce energy consumption and lower your heating bills.

What’s the importance of regular maintenance for my heating system?

Regular maintenance helps ensure your heating system operates efficiently, prolongs its lifespan, and reduces the risk of unexpected breakdowns. It also contributes to energy savings and a comfortable home environment.

Are smart thermostats better than traditional ones?

Smart thermostats offer advanced features such as remote control via a smartphone app and learning capabilities to adapt to your schedule. They can be more energy-efficient, but the choice between smart and traditional thermostats depends on your preferences and needs.


In conclusion, troubleshooting a Honeywell thermostat blowing cold air on the heat setting involves a systematic approach. Start by verifying the thermostat settings, power supply, and inspecting the HVAC system for issues.

Check for obstructions, clean or replace air filters, and ensure correct thermostat wiring. Calibration, programming, and software updates can also be crucial. If the problem persists after thorough troubleshooting, don’t hesitate to contact a professional HVAC technician for a more in-depth diagnosis and repair.

Regular maintenance remains essential to prevent future heating issues and ensure your home’s comfort and energy efficiency. Addressing thermostat problems promptly ensures a warm and comfortable living space during the colder months.

Scott Maupin