AC Thermostat Keeps Resetting to 85—What to Do?

Facing issues with your thermostat, such as unexpected resets to 85 degrees Fahrenheit?

Whether you're dealing with Honeywell thermostat troubleshooting or figuring out how to fix a Braeburn thermostat, understanding the common causes can be helpful.

Here's a quick overview:

  • You have the thermostat programmed to 85 degrees
  • The batteries need replacement
  • The thermostat has a blown fuse or wiring issues

Some issues can be fixed quickly, while others might need an HVAC technician's expertise.

Continue reading to diagnose and remedy the situation.

A hand adjusting temperature on smart thermostat, AC Thermostat Keeps Resetting To 85—What To Do?

Potential Reasons Why Your Thermostat Keeps Resetting to 85 [+How to Fix]

Below, we explore potential reasons why your thermostat keeps resetting to 85.

Thermostat Programmed to 85 Degrees

New thermostats might have pre-set factory temperatures.

Someone in your home could've set it, or if you've moved recently, it might've been pre-programmed to 85°. Always review the settings if it resets often.

Batteries Need Replacement

For non-programmable thermostats, outdated batteries can be an issue. Even if you believe you've recently replaced them, they might be older than you think.

In rare instances, very old batteries might leak acid, damaging the thermostat.

Blown Fuse

Resetting issues can often stem from a blown fuse in your thermostat, causing it to malfunction and reset.

To identify this, inspect the thermostat for a colored fuse, often resembling a small clear cylinder. A broken filament inside suggests it's blown.

While replacing the fuse can be straightforward, if you're not confident with electrical tasks, consult a professional. Typically, it's a quick fix.

Wiring Issues

Older thermostats can have loose or faulty wiring, leading to malfunctions.

While some issues are evident, like visibly damaged wires, others might be less obvious. In some cases, the wires can simply go out and fail to provide continuity.

If you suspect wiring problems, it's best to seek help from an HVAC technician or electrician for repairs or replacement.

Continue reading: Thermostat Not Shutting Off When Reaching The Temperature – What To Do?

How Do You Know a Thermostat is Bad?

A thermostat set to 68 degrees for the kitchen area

Often, a thermostat will display signs that it is due for a replacement. Here are the most common ones:

  • HVAC system powers on and off: The thermostat might have issues if the HVAC frequently turns on and off, often due to damaged wires or a weak battery.
  • Incorrect temperature readings: If the thermostat shows wrong temperatures even after resetting and changing batteries, it may have wiring issues or need replacement.
  • Constant temperature fluctuations: A faulty thermostat can unpredictably change settings or fail to maintain the programmed temperature.
  • HVAC system short cycles: If the HVAC shuts on and off too quickly, known as short cycling, it could be a sign of a worn-out thermostat or bad wiring.

Why Does My Thermostat Keep Dropping Temperature?

As explained earlier, it may need recalibration due to the thermostat adhering to a pre-set temperature.

Furthermore, like any device, thermostats wear out. If yours is over a decade old and acting up, consider having it checked by an HVAC expert.

That said, other external factors can play a part. Here are a couple of potential culprits:

The Outdoor Unit is Frozen

During extremely cold temperatures, coming into the thermostat may drop below its setting due to a frozen outdoor unit.

If the evaporator coils in the outdoor unit are blocked by ice, the unit will not be able to transfer heat using the refrigerant inside them.

As a result, the thermostat will not be able to raise and maintain the temperature of the home. You'll need to clear the coils to fix this issue.

An Incorrectly-Sized Furnace

An inappropriately sized furnace can cause serious issues inside a home.

For example, if the furnace is too small, it will lack the power to sufficiently heat the home, causing the thermostat to fail to reach the desired temperature.

Conversely, a furnace that is too large may warm the air too quickly, causing it to overheat faster than the thermostat anticipates.

Related content: Room Temperature Doesn’t Match Thermostat Setting—What To Do?

How Do I Reset the Thermostat on My AC?

You can perform a reset on your thermostat in one of two ways.

You can press the reset button on the thermostat itself, granted the thermostat has a reset button.

Or, you can perform a manual reset using the circuit breaker box. Here are the steps to follow:

  1. Locate your circuit breaker and a d control for your HVAC system. Make sure the HVAC system is off first.
  2. Next, find the control label for the HVAC system and flip the circuit breaker to the off position.
  3. Then, wait 30 to 40 seconds and slip it back to the on position.
  4. Turn the HVAC system back on and see if it works again.

Here's a Youtube video to help you along the way.

Why Does My Braeburn Thermostat Keep Resetting to 85?

Braeburn thermostats occasionally reset to 85°F due to various reasons.

Electricity Interruptions

Sudden electricity interruptions, like power surges or brief outages, can momentarily disrupt the thermostat's operation.

When the power returns, the thermostat might default to its initial setting, which in some cases is 85°F.

Low Battery

As batteries wear out, they might not provide consistent power, causing the thermostat to revert to default settings.

Unsecured Connections

Loose or unsecured wiring can also be a culprit. If the wires aren't firmly in place, it could result in sporadic functioning and resets.

Malfunctioning Thermostat

Sometimes, the issue could be from manufacturing defects or general wear and tear, causing the thermostat to behave unpredictably.

System Mismatch

If your Braeburn thermostat and HVAC system aren't fully compatible, it may repeatedly default to 85°F.

How to Fix a Braeburn Thermostat That Keeps Resetting?

Woman reset the thermostat

When your Braeburn thermostat keeps resetting, it's time to troubleshoot. Here's a simple guide:

  1. Check the power: See if there was a recent power cut. If the display looks dim or blank, it might be time to change the batteries.
  2. Review the settings: Check the settings and ensure it's not on a default temperature you didn't pick.
  3. Test the batteries: A faulty battery can be the issue even if you recently changed them. Try using a fresh set to see if it helps.
  4. Update modes: Make sure the cooling or heating modes are suitable. A wrong setting might make it keep resetting.
  5. Update firmware: Also, consider updating your thermostat's firmware. You can find updates on Braeburn's website. This usually fixes glitches with your settings.
  6. Reset: As a last resort, try giving your thermostat a full reset. This can clear any minor glitches.

📌 You can get information on resetting your Braeburn thermostat by following the user manual.

If it's still acting up after trying these fixes, it might be best to call a technician. They can help identify and solve more complex issues.

Here's a helpful video that can help you around with setting your Braeburn Thermostat correctly.

Why Does My Honeywell Thermostat ProSeries Keep Resetting to 85?

If your Honeywell Thermostat ProSeries keeps resetting to 85 degrees, it likely needs some programming.

The reason is usually due to the pre-set temperature, which is 85 degrees for cooling.

To address this, you'll need to focus on programming and adjusting settings.

Here's how to crack the code:

Get Acquainted with Programming

Start by learning how to program your thermostat. This is your ticket to regaining control.

Time it Right

If you're dealing with a 2-time thermostat, sort out your occupied and unoccupied times. Set your desired temperatures for when you're present and away.

If you're dealing with a 4-time thermostat, understand the wake, leave, return, and sleep times and set the corresponding temperatures.

If they come with specific times, ensure they're all set.

You can refer to this video on programming your Honeywell thermostat.

Additionally, you can refer to Honeywell's troubleshooting page for a more comprehensive guide on your specific situation.

You might also like: How To Control A Honeywell Thermostat From Your Phone [Step By Step Guide]

How Much Does a Thermostat Cost to Replace?

How much does it cost

The cost of a thermostatic self will vary by brand and model, though it can range anywhere from $20 to over $200.

The cost to have a contractor replacement for you will typically range anywhere from $50 to $150 or more.

Wrapping Things Up

Addressing unexpected thermostat resets to 85°F requires a methodical approach.

By understanding common causes, troubleshooting steps, and potential external factors like frozen units or furnace size, you can effectively resolve this issue.

Have the concepts covered in this article shed light on your thermostat troubles?

We'd love to hear your thoughts and whether our insights have helped you pinpoint and fix the error.

Feel free to share your feedback and experiences with us!

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A man adjusting the thermostat, AC Thermostat Keeps Resetting To 85—What To Do?

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