my ac thermostat is reading the wrong temperature

Should I worry if my AC thermostat is reading the wrong temperature? Your thermostat is a crucial part of your HVAC system that lets you set the perfect cooling and heating routine. However, if it no longer reads the correct temperature, the problems may go beyond not being able to set the right temperature level in your home. 

Below, the team at Lion Air Conditioning Cooling And Heating, LLC discusses this issue in more detail, including when it may be time to schedule air conditioning repair in Margate, FL.

Reasons Your Thermostat Could Be Reading the Wrong Temperature

Normally, a thermostat monitors indoor temperatures while changing the heating or cooling to match the programmed level. However, the thermostat’s calibrations are highly sensitive and malfunction easily. For example, if the thermostat reads 75 degrees F when it is really 65 degrees F, the unit might change the setting unnecessarily and start increasing your monthly energy bills.

An accurate thermostat can save a significant amount in heating and cooling costs over the years. Here are some checks a professional might do if the thermostat suddenly starts going wrong:


Many thermostats run on batteries, whether they are AA, AAA, 9V, or lithium disc batteries. If the batteries run low, the thermostat reading and panel might start to malfunction. Most modern thermostats have a handy indicator of the unit’s battery level to tell you when you need to replace them.

Is your thermostat wired into the wall? You don’t have to worry about batteries. If not, check the batteries for corrosion. Don’t touch the cells with bare hands, and use gloves to dispose of them if corrosion is present.

Thermostat Placement

Thermostats need to be in the right place for the most accurate temperature readings. For example, it might register a higher reading if it is right next to a vent. If it is next to a window, the amplified effect would probably be a colder temperature.

The ideal position for a thermostat is about five feet from the floor. It should be on an open wall with no doors or windows nearby. Wired smart thermostats will need an expert to assist with rewiring.

Dust Covering the Sensor Plate

Many modern digital thermostats use a temperature sensor called a thermistor that measures the electrical resistance between two plates. The plates change shape with the temperature, changing the electrical resistance and allowing the thermistor to convert it into an accurate temperature reading. If my AC thermostat is reading the wrong temperature, check the sensor plate.

Dust and debris lead to inaccurate readings on the thermistor. You can clean the dust off the internal components using a soft paintbrush or compressed air. However, if the thermistor damage is extensive, an expert may recommend replacing the thermostat instead.

Thermostat Not Level

Older thermostats read the height of the mercury switch to determine the temperature. If the tube has moved off-balance, these old-style thermostats will start showing incorrect temperatures. It is not uncommon for thermostats to shift slightly after installation, and readjusting their position can often fix the problem.

Loose Wiring

Loose wires present another possible reason your air conditioning thermostat setting could be reading the wrong temperature. Wiring that moves around can cause current fluctuations that turn the thermostat on and off. The process messes with the calibration without fast intervention.

Is there damaged wiring visible? Our team would need to replace these wires before reattaching the thermostat. Loose wiring can be dangerous, so be sure to call an expert to replace it safely.

Old Age

Last but not least, improper temperature readings could be a sign that the unit has reached the end of its useful life. Wear and tear in the components may require repair or replacement, depending on the age and condition of the cooling unit. Typical modern thermostats last about ten years, though replacing them sooner does offer you access to the latest technological improvements.

Cooling and Heating Services in Coral Springs, FL

Is your thermostat reading the wrong temperature? Is your air conditioner more than ten years old already? You might want to consider replacing it.

Whether you need to change your air filter or schedule a new installation, our experienced team provides industry-leading air conditioning repair and maintenance services. With over a decade of experience, we have an established track record of superior customer service.

Does my unit need repair or replacement if my AC thermostat is reading the wrong temperature? Find out from Lion Air Conditioning Cooling And Heating, LLC online or call (754) 225-6051 to schedule thermostat services in Coral Springs, FL.

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