“Is your Honeywell thermostat displaying a warning sign, a triangle with an exclamation point?
Don’t panic! In this troubleshooting guide, we’ll walk you through simple steps to decode the symbol and get your thermostat back to optimal performance in no time.”
A thermostat displaying a triangle with an exclamation mark is simply telling you that there is something with your system that needs attention.
This can be anything from a dirty air filter that needs a replacement to a critically low battery.
It can be hard to tell exactly what the issue is until you manually check the code that is triggering the warning sign.
To check the underline code behind the warning sign, follow these steps below:
Step 1: The alert icon appears on the Home screen.
Step 2: Press Menu, and then press until the display shows ALRT.
Step 3: Press ‘Select’ to display which alert(s) are present.
Step 4: The message REPL (REPLACE AIR FILTER) appears.
Not that the reminder can be snoozed or cleared. But it’s recommendable to change the air filter before clearing the reminder.
To snooze the reminder, press ‘Select’. The word SNZE (SNOOZE) appears.
- Press Select again to snooze the reminder for 7 days.
To clear, press Select, and then press to go to CLER (Clear).
- Press Select to clear the air filter reminder
The following table shows some of the codes that can trigger the triangle symbol with exclamation point.
| Code | Issue |
| 164 | Heat pump needs service |
| 170 | Internal Memory Error |
| 173 | Thermostat thermostat temperature sensor Error |
| 181 | Replace Air Filter |
| 405 | Low battery |
| 407 | Critically low battery |
164
Heat pump needs service. This reminder is mostly based on the number of hours the HVAC system has been in use. It is not necessary that there is a need for service.
As a good rule of thumb it is recommended to service your HVAC system at least once a year. More, even better.
During annual tune ups, the technicians will also perform preventive measures to prevent your system from unforseen breakdowns
Read also: Honeywell Thermostat Symbol Meanings Explained
170
The memory of the thermostat has encountered an error. Please contact dealer for assistance
173
The sensor of the thermostat has encountered anerror. Please contact dealer to replace the Thermostat
181
Replace air filter. The timer however has no idea on the status of your air filter. It is just programmed to alert after a certain number of hours.
I would advise you to start by replacing your air filter before you reset the reminder.
After you have replaced your filter, reset the timer by touching the “dismiss” button on the thermostat screen after it is replaced.
Read also: Honeywell thermostat filter reset
405
This code means that the batteries are getting low. You need to replace your thermostat batteries at least once a year.
But when you see this code on your thermostat, you should replace them within two months.
407
With this code, your thermostat batteries are nearly dead and you should replace them as soon as possible. Get high quality batteries from a known manufacturer.
Final thoughts
In conclusion, encountering a warning sign on your Honeywell thermostat in the form of a triangle with an exclamation point shouldn’t cause panic.
It is a way for your thermostat to communicate that there is an issue with your system that requires attention.
By following the troubleshooting steps outlined in this guide, you can identify the specific problem behind the warning sign and take appropriate action.
Read also: Honeywell Thermostat Low Battery Symptoms And How to Replace Batteries
Remember that the underlying issue could be something as simple as a dirty air filter or low battery levels.
Regular maintenance, such as replacing the air filter and thermostat batteries, can help ensure optimal performance and prevent potential problems.
Additionally, understanding the various codes associated with the warning sign enables you to determine the nature of the issue.
Some codes may indicate the need for professional assistance, such as heat pump servicing or thermostat sensor replacement.
More resources on the official Honeywell site can be found here.
Honeywell Thermostat - Warning Sign FAQ's
What does the triangle with an exclamation mark mean on my Honeywell thermostat?
This warning symbol indicates that your Honeywell thermostat has detected an issue that requires your attention. It could be something straightforward, like a dirty air filter that needs replacing, or more critical, such as an internal memory error. The thermostat uses this symbol to make you aware of potential issues that might impact the efficiency of your HVAC system or the comfort level in your home. Addressing these warnings promptly is crucial for maintaining the system’s longevity and ensuring optimal performance.
How do I access the error code on my Honeywell thermostat?
To access the error code, start by locating the “Menu” button on your Honeywell thermostat. Press the “Menu” button, then navigate using the arrow buttons until you see “ALRT” displayed on the screen. Once you see “ALRT,” press the “Select” button. The screen will display any current alerts along with specific codes that help you identify the issue. This process helps you understand exactly what the thermostat is warning you about so that you can take the appropriate action to resolve it. Always refer to the manual for specific codes and recommendations.
How do I fix the "Replace Air Filter" warning?
If you see the “Replace Air Filter” warning, it’s time to replace the HVAC system’s air filter. First, ensure that you have the correct filter size for your system, which you can usually find in your system manual or on the old filter itself. Turn off the HVAC system before replacing the filter to ensure safety. Once replaced, you can reset the reminder by navigating back to the alert on your thermostat and pressing “Select” to clear it. Regularly replacing the air filter, ideally every 90 days (or sooner if you have pets or allergies), ensures proper airflow and keeps your HVAC running efficiently.
What type of batteries does my Honeywell thermostat need?
Most Honeywell thermostats use either AA or AAA batteries, but it’s important to refer to your thermostat’s user manual to confirm the exact type. The thermostat will usually indicate a low battery warning well before it runs out, giving you time to replace them. Use high-quality batteries from a reputable manufacturer to ensure they last longer and provide consistent power. Avoid mixing old and new batteries, as this can affect the thermostat’s performance and even cause the warning symbol to persist.
Can I ignore the warning sign on my Honeywell thermostat?
Ignoring a warning sign on your Honeywell thermostat is not recommended. While some warnings may seem minor, like a low battery or a filter replacement reminder, they can lead to bigger issues if left unattended. A clogged air filter, for example, can cause your HVAC system to work harder, leading to higher energy bills and potentially reducing the system’s lifespan. Low batteries can result in inaccurate temperature readings or cause the thermostat to lose its settings. Addressing these warnings promptly ensures that your HVAC system continues to function smoothly and efficiently.
Why does my thermostat keep displaying the "Low Battery" warning even after replacement?
If your Honeywell thermostat continues to display a “Low Battery” warning after you’ve replaced the batteries, several issues might be at play. First, make sure that the new batteries are high-quality and not expired. Cheap or old batteries may not provide sufficient power. Also, double-check that the batteries are installed correctly, with the positive and negative ends in the correct orientation. If the warning persists, there may be corrosion on the battery contacts inside the thermostat. Gently clean the contacts using a dry cloth or a small amount of rubbing alcohol. If these steps do not resolve the issue, it may indicate a more serious problem with the thermostat that requires professional servicing.
How often should I replace my air filter?
The frequency of air filter replacement depends on several factors, such as the type of filter, the number of people and pets in the home, and any allergy concerns. A good rule of thumb is to replace standard air filters every 90 days. However, if you have pets, it’s best to replace them every 60 days, or even every 30 days if anyone in the home has allergies or respiratory issues. High-efficiency filters may last longer but should still be checked regularly. Regular replacement ensures your HVAC system runs efficiently, improves indoor air quality, and helps prevent unnecessary wear and tear on your system.
Is there a way to clear the alert without fixing the issue?
You can technically clear or snooze some alerts on your Honeywell thermostat without fixing the issue, but this is generally not advisable. For example, a “Replace Air Filter” alert can be snoozed for 7 days if you press “Select” when the alert is displayed. To clear it entirely, navigate to the alert, press “Select,” and then press again to go to “CLER” (Clear). However, ignoring such alerts can lead to decreased system efficiency, higher energy bills, and even costly repairs. It’s always better to address the underlying cause before dismissing the reminder.
What should I do if the thermostat displays an internal memory error?
An internal memory error (Code 170) indicates that the thermostat has experienced a failure in its internal memory, which could impact its ability to store or retrieve settings. In this case, it’s best to contact Honeywell customer support or a licensed HVAC technician. They can determine if the thermostat requires a reset or if the memory error is a sign of a larger issue that necessitates replacement. Attempting to fix an internal memory error yourself could lead to further issues, so it’s best left to a professional.
What should I do if my thermostat displays the heat pump service warning?
The heat pump service warning (Code 164) is typically a reminder based on usage hours rather than a detected fault. It’s still important to heed this warning and schedule a professional service. Regular heat pump maintenance, ideally once a year, ensures the system runs efficiently and prevents unexpected breakdowns. During service, a technician will check refrigerant levels, clean components, and make sure everything is functioning properly. Even if there is no immediate issue, a tune-up helps maintain system efficiency and extend its lifespan.
Where does the triangle with exclamation point come from?
The triangle with an exclamation mark on Honeywell thermostats serves as a universal warning indicator, alerting users to potential issues within their HVAC system. This symbol is designed to capture attention promptly, signaling that the system has detected a condition requiring user intervention.
Design and Purpose
The triangle is a widely recognized caution symbol, and the inclusion of an exclamation mark emphasizes the need for immediate attention. In the context of Honeywell thermostats, this alert is part of the device’s diagnostic system, programmed to notify users of various operational concerns.
Common Triggers
The warning symbol can be activated by several conditions, including:
- Maintenance Reminders: Alerts for routine tasks such as replacing air filters.
- System Errors: Indications of malfunctions like sensor failures or internal memory errors.
- Battery Alerts: Notifications of low or critically low battery levels.
Accessing Detailed Alerts
To identify the specific issue associated with the warning symbol, follow these steps:
- Press the “Menu” button on your thermostat.
- Navigate to the “ALRT” (Alert) section using the arrow buttons.
- Press “Select” to view active alerts and corresponding codes.
Each code corresponds to a particular issue, as outlined in the thermostat’s user manual.
Usage Across Honeywell Models
While the triangle with an exclamation mark is a standard warning indicator across many Honeywell thermostat models, the method to access and interpret alerts may vary. It’s essential to consult the specific user manual for your thermostat model to understand the exact procedures and codes.
Importance of Prompt Attention
Addressing these warnings promptly is crucial to maintain the efficiency and longevity of your HVAC system. Ignoring alerts can lead to decreased performance, higher energy consumption, and potential system failures.
For a visual explanation of the triangle symbol on Honeywell thermostats, you may find the following video helpful:
