Solid red light on air conditioner

Solid red light on air conditioner. If it is a hot summer day outside and suddenly your AC is malfunctioning then try to get panic. Sometimes it happens that the solid red light on the thermostat is on or blinking when the compressor of the AC is closed down due to any reason.

As you already know that the compressor is the outside part of the AC. If it is shut down due to any reason like a power issue then it will convey a signal to the thermostat.

In spite of that signal, the inner AC unit will not get any message and continue to run without knowing there is trouble in the outside part.

You will get familiar with the issue when you observe that the room is getting warm and there is less cooling in the room now. In this article, I will tell you about the easiest solutions to this issue or I will inform you to hire a professional person

Solid red light on air conditioner

solid red light on air conditioner

It is very stressful to see the red light blinking on any electrical appliance in the home. It is a sign of something malfunctioning in the device.

Now coming to our article, if you check the solid red light on the thermostat of the air conditioner then don’t worry it is not a big issue.

Here are possible reasons and solutions to fix this issue.

Compressor not getting power

In summer the demand for power is more than in the winter season. Due to the overload, sometimes the air conditioner’s circuit breaker is tripped from the main box or its fuse is blown away.

Due to any of these reasons the compressor of the AC loses power and the red light starts blinking on the thermostat.

You can fix the issue by replacing the circuit breaker or fuse if that is blown away. The red light will automatically off when the loss of power issue will be solved.

The condenser fan motor is burnt

If you are not maintaining the unit carefully by cleaning it properly then its motor can be burnt out due to the wear and tear.

If the fan motor is too old then the capacitor of the motor can also damage it. Simply replacing the burnt motor with the new one can fix the issue of red light blinking on the capacitor.

The capacitor is worn out

the capacitor is worn out

The capacitor is the most important component of the compressor as it works like a battery it keeps the energy that is required by the compressor to work.

If your unit is out of warranty card then its capacitor will also be too old and maybe worn out due to depletion and its red light will send the signals to the inner part of the unit.

Now if it becomes faulty due to overuse then it will affect the condenser motor as well as the compressor also. As a result, the unit will shut down.

So it is better to replace the worn-out capacitor immediately otherwise it can burn out the fan motor and other parts also because their load will be increased.

Issue of short circuit

If there is an issue with the wiring in the system then the AC unit will stop working. Sometimes there is a short circuit in the wiring of the unit then solid red light starts blinking on the thermostat to inform you that something is wrong.

So whenever you check that the red light is on then immediately check all parts of the unit and wiring and fix the problem to save yourself from big hazards.

High-pressure problem

As you know that the switch of the unit is high pressure and it will automatically of the capacitor when there will be low pressure of the power or very high pressure of the electricity in the system.

This issue also arises when there is no proper cleaning of the components like condenser coils are full of dust and blades of the fan are circulating in the wrong direction etc.

When it happens, the pressure on the switch increases, and the red light starts to blink on the thermostat. If you have such type of power issues then it is better to call a certified technician to troubleshoot.


Solid red light on air conditioner. The bottom line of the article is that if you observe that cooling is decreasing in the room although the air conditioner unit is running inside, then first of all inspect the thermostat.

If a red light on the thermostat is on then it is a sign of something wrong with your unit. All possible reasons are mentioned in this article to fix the issue.

If still, you did not find the cause then you can hire a professional for further inspection.

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