Why is the temperature in my home higher than my thermostat setting?

We’ve seen this issue many times as an air conditioning repair company. In this article, we want to shed light on possible reasons why there might be a discrepancy between the temperature and the thermostat setting and what steps may rectify the situation.

Things to check if your home has a higher temperature than your thermostat

Here are some items to check when attempting to determine if the thermostat is working properly as well as how to fix potential thermostat problems.

Dirty or Clogged HVAC Filter

If your air conditioner or heater can’t breathe in, it can’t breathe out. Locate your filter, then remove and replace it. They are inexpensive so buy a few extra. It isn’t necessary to note the make and model number of your HVAC, just the filter size that is clearly stamped on the side of the filter itself. It should be changed every 3 months (seasonally). While you are at it, you can upgrade to a HEPA filter. The pores are much smaller so they really, really filter the air prior to blowing it back into your home. Visit our Corpus Christi store where you can discuss all things HVAC and buy a few filters without wasting time in a big box store.

Obstructed or Dirty Vents

You might just have your furniture covering the wall or floor vent. When was the last time that you had your ductwork cleaned? With the right tools and know-how, it is a pretty quick job. You will likely be shocked at the amount of filth and pet hair that is stuck to the walls of the ducts. If you are not up for the job, we can do it for you.

Attic Insulation

If you notice that some rooms are hot and others are not, it may be a quick fix to add insulation to the attic. There are precautions to make sure that you don’t just add it on top of the existing insulation and trap moisture between the layers. Invite us to your home for a free insulation inspection and quote.

Faulty Thermostat

If your home is older than 20 years, you may still have an analog thermostat. It uses a glass cylinder filled with mercury which moves left or right to complete the circuit based on the indoor temperature settings. The movement is mechanical and the switches are mechanical. They wear out.

Thermostat Location

Have you built an addition to your home or moved the location of your thermostat? Incorrect placement can result in inaccurate temperature readings and, as a result, make the HVAC system run either too long or not enough.

Ideally, the thermostat should be positioned
– in a central place
– out of direct sunlight
– that sees frequent use
– and where natural air circulation occurs.
– at a height of 52” to 60”

It is best not to place a thermostat in a spot where there is a cold draft from windows or where there is warm air from a kitchen. This makes it nearly impossible to have an accurate reading of the ambient temperature in your home.


Are you a DIY person?
Explore these potential causes for inconsistent temperature in your home. Remember to disconnect the power supply before removing the access panels – Safety First.

Check the Temperature Sensor

The thermostat sensor is located near the evaporator coils inside your air conditioner unit. As air from the return vents passes by the sensor, it reads the temperature and compares that reading to the setting on your thermostat. When the sensor isn’t working correctly, it may cycle on and off randomly between proper activation periods causing your home to be either too hot or too cold due to the thermostat switching on and off before the correct temperature is met.

  1. Start by turning off the air conditioner.
  2. Then, shut off all power by using the breaker at the electrical panel.
  3. Remove the cover on the inside HVAC unit in order to expose the evaporator coils.
  4. The sensor needs to be close but not make direct contact with nor be too far away from the coils. If you aren’t sure of the sensor’s proper placement, it is best to call a professional HVAC technician to complete the repairs.

Check the Blower Motor

Blower motors are designed to circulate air. If there is no air to move, then the blower won’t work. Always check the filters and vents surrounding the blower to make sure that the blower isn’t struggling. If the arrows on the air filter are pointing in the wrong direction, change the orientation of the filter. Then, check the vents around the blower. If the vents are closed or clogged, your blower may be too dirty to work. If the blower looks dusty, spray the dust away with compressed air or simply wipe it away with a rag.

Check the Power Sources

First, make sure the thermostat has power. Some thermostats have batteries that can go bad. Swap out the batteries and see if that corrects the thermostat readings. If the batteries are good, then look at other power sources in your home like blown fuses and tripped breakers. If you suspect that the issue may be a breaker or fuse, you may need to hire an electrician to fix the problem.

A hand holding up an phone displaying all temperature controls for the home

Upgrade the Thermostat

Digital thermostats are inexpensive and pay for themselves quickly in energy savings. Digital thermostats allow you to program a schedule for the air conditioner and heating system, making your home more energy efficient. See our smart home bundles.

How Does a Thermostat Work?

All thermostats work by sending a current through an internal component called a thermistor. This measures the resistance of the current and helps calculate the indoor temperature. The thermostat uses the indoor air temperature to compare to the preset temperature. When there is a variation between the two, the thermostat sends a signal to the HVAC unit, which then turns on or off to alter the room temp closer to the desired temperature.

The better thermostat you have, the more efficiently your HVAC system will run. If your thermostat is older than ten years, your system will more than likely run better with an upgrade to a programmable thermostat. Even if you already have a programmable thermostat, newer smart thermostats can mean lower heating and cooling costs. If you answer yes to any of these questions – it’s time to upgrade your thermostat:

  • Your thermostat isn’t programmable
  • Your thermostat is older than 10 years old
  • Your thermostat gives faulty readings
  • Your thermostat doesn’t respond to changing settings
  • Your HVAC system short cycles
  • You have suspiciously high energy bills

Maybe the Weather is Just Too Hot!

In Corpus Christi, especially in the summer, the outside temperatures are soaring. It could be that your thermostat and HVAC system is not able to keep up. It’s natural to want to set the air conditioner at a lower temperature to stay comfortable during extreme heat. At the same time, you want to use the desired temperature that won’t increase your heating and cooling costs.

The best temperature setting in your house during the summer is 78 degrees when you are home. If you are away from your home for an extended period of time, it’s good practice to raise the setting or even turn it off entirely. Programmable smart thermostats can help make it easy to monitor your home’s temperature while away, and Google nest thermostats can sense motion or connect to your phone and use your location to turn off or adjust the temperature automatically.

Contact Precision Air for Your HVAC and AC Repair Needs

We have experience in troubleshooting temperature and thermostat variances. Our team has the knowledge to get to the core of the problems you may be experiencing with regulating the temperature in your home. If you are stumped, call us or schedule an appointment online. We’ll be right there.

Eli Castaneda Jr. - founder and owner of Precision Air
I’m Eli Castaneda Jr,

 I’m the founder and owner of Precision Air. We are a family-owned business providing air conditioning and heating services to homeowners and businesses in Corpus Christi and the Coastal Bend area of Texas.

With over 23 years in the industry, I am using everything that I have learned serving thousands of customers to ensure that my team delivers precise, dependable, and high-quality service whenever you need it; day or night. We value your business.

If you live in the Corpus Christi area and need to have your HVAC serviced or replaced, give us a call!

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