Although circuit breakers are very important safety devices in our homes, it can, however, become very frustrating if a circuit breaker is tripping regularly due to a faulty appliance or wiring. When your thermostat breaker keeps tripping it causes problems throughout your whole HVAC system. 

The three most common reasons why your thermostat breaker keeps tripping are either a circuit overload, a short circuit, or a ground fault. 

In this article, we’ll discuss how electricity and circuit breakers work, and how to determine the reasons why your thermostat breaker keeps tripping.

Background – Electricity and electric wiring

To explain what to look for when an appliance like your thermostat breaker keeps on tripping, we’ll have to quickly look at what electricity comprises and how home and appliances are wired.

What is electricity?

The three components of electricity are voltage, current and resistance. 

  • Voltage is the “pressure” to make the electric charge move through the conductor. 
  • Current (measured in amperes) is the rate at which it flows. 
  • Resistance (measured in ohms) occurs when the current interacts with the conductor.

Materials have different levels of resistance. Some materials are excellent conductors for electricity, while others are not. Some materials are such weak conductors that they are used as insulating materials. 

Electrical wiring of your home and appliances

In principle, all electrical wiring should be done in the same way, whether it is the wiring of your home or the wiring of an appliance, including the HVAC thermostat.

Normally, the wiring consists of three different types of wires: 

  • a hot wire for conducting the electric current,
  • a neutral wire, and
  • a ground wire. 

The hot and neutral wires should normally never touch each other. 

The role of a circuit breaker

When the electric current passes through an appliance, the appliance applies a high level of resistance to the current. This is necessary to keep the voltage at safe levels. 

If something causes the hot and neutral wires to come into contact with each other, the current encounter a reduced resistance, and that can cause voltage and current levels to become very high. This can even cause a fire. 

Therefore, when current and voltage levels are becoming too high on a circuit, the circuit breaker trips. The role of the breaker is to cut off electricity to the circuit. The breaker will keep on tripping when you put it on again until the issue has been resolved.

How to reset a tripped circuit breaker

To reset a tripped circuit breaker, you first have to completely turn off the breaker by moving the switch to the off position. After you’ve “clicked” it into the off position, you turn it back on.  For safety, it’s a good idea to stand back or to the side of the panel, just in case any sparks are coming. 

It’s also a good idea to keep a flashlight near your electrical panel to illuminate the breakers when the power is off. 

There are videos available that will take you step-by-step through the resetting procedure of a circuit breaker.

Most common reasons why your thermostat breaker keeps tripping

As we’ve said at the beginning of this article, a circuit breaker normally trips because of a circuit overload, a short circuit, or a ground fault. They are the most common reasons for your thermostat breaker to keep tripping. Let’s look at why and how these aspects allow the thermostat to trip the breaker.  

As a result of a circuit overload

Simply put, a circuit becomes overloaded when it receives more amperage than it’s designed for. A circuit overload can also be the result of loose or corroded wires and connections. 

Often a circuit overload occurs when too many appliances are plugged into the same circuit. If most of your HVAC and other electric appliances are plugged into only one circuit, the circuit might be utilized to its maximum when all appliances are working simultaneously. 

When even a little bit of extra amperage is needed it can trip the breaker. If your thermostat breaker trips whenever the thermostat has to register new climate readings, it might not be a problem with the thermostat but is actually an overload problem.

To resolve this problem, plug some of your HVAC and other electric appliances into another circuit. If the problem persists after you’ve done this, you’ll have to look at other possible reasons for the tripping.     

As a result of a short circuit

A short circuit occurs when a hot electrical wire and a neutral wire touch. This also causes an overload as a large current flows via the circuit.  A short circuit should always trip a breaker – it is one of the most important functions of a circuit breaker because a short circuit can easily start a fire.  

If there is a short circuit in your thermostat the breaker will trip every time after you’ve reset it. Generally, a short circuit in the thermostat is caused by a faulty electrical switch or loose connections and wires. 

To rectify this problem, put off the power supply and open the thermostat’s holder. Tighten loose connections if you see any, close the holder and put on the power again. If the breaker is not tripping anymore, you’ve solved the problem. 

If the problem persists, you’ll have to keep on searching for other possible reasons.

As a result of a ground fault

When hotwire makes contact with the ground wire or a grounded portion of the appliance, it is called a “ground fault.” When this type of contact is made, large amounts of current flow through the circuit breaker. Normally, this trips the breaker. 

It must be noted that a ground fault in your thermostat must be repaired as soon as possible. A ground fault poses danger as live electrical parts are not protected anymore and you can get an electric shock when touching any part of the thermostat.

As in the case of a short circuit, you have to put off the power and open the thermostat holder. If you can see where the faulty contact is made, repair it – normally by placing the wire in place again and tightening it. 

If you can’t repair the fault yourself, call a professional service provider to inspect the thermostat and to either repair or replace it. 

Apart from these three most common reasons why your thermostat breaker keeps tripping there are other possible reasons you should also consider.

Proximate causation 

If your thermostat doesn’t have a separate circuit breaker but is sharing the circuit with other appliances, it might be one of these other appliances encountering the electric problems and causing the tripping of the breaker and not the thermostat. 

So, if the inspection of your thermostat has not shown any sign of short-circuiting or a ground fault, unplug the appliances one after the other and every time test whether the tripping is continuing.  

The tripping of your thermostat breaker can also happen when the thermostat activates an appliance with a malfunction, and that appliance is on the same circuit. This is called proximate causation. 

Bad circuit breaker 

Circuit breakers normally have a long lifespan but at a stage, they can get bad and have to be replaced. 

One of the symptoms of a bad circuit breaker is that it starts tripping without reason. If you’ve checked for all the possibilities why your thermostat breaker keeps tripping and couldn’t find anything, you have to consider that the circuit breaker itself can be faulty. 

A professional electrician will be able to determine whether this is the case and if so, replace it with a new one. (Please remember that replacing a circuit breaker is normally not a DIY job if you are not a qualified electrician!)


As discussed in this article, there are various reasons why your thermostat breaker might keep tripping. You can troubleshoot for the most common reasons and in many instances rectify the problems yourself. 

But if your troubleshooting at the thermostat itself and all the other applications on the same circuit has not revealed the problem and the problem persists, you have to get a professional electrician to attend to the problem.

Remember, there is always a reason why a circuit breaker trips and for safety reasons, it cannot be ignored if it keeps on tripping. 


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