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Blown Fuse: What Can This Mean To Your Aircon Unit

What is an aircon unit fuse?

A fuse, no matter if it’s in your Christmas lights, your car, or in your aircon unit, is a safety device. Fuses prevent too much electrical current from passing into your electrical equipment. A fuse is a metal filament or wire, usually in some type of casing. It’s located in the disconnect box, connected to your aircon unit. It is there to protect your machine, to avoid more serious aircon issues. It does this by stopping the flow of electricity whenever an overload of electricity occurs, the filament melts and stops the flow of electricity.

At their simplest, they are metal wire that melts when exposed to too much current, breaking the circuit and shutting off the electrical system, like your aircon unit. Another way to break current to possibly faulty equipment is a circuit breaker, and your heating and an aircon unit probably have both.

How do I know if my aircon unit fuse is blown?

If you think that your aircon unit may have blown a fuse, your best course of action should be to consult a professional aircon servicing company, especially if this is not the first time this has happened.

You can tell if your fuse is blown by checking the outdoor unit. If the aircon unit isn’t doing anything except producing a slight humming sound despite having no power, you may have a blown fuse on your hands.  You can be sure that something has gone wrong when this happens. The fuse itself is almost never the problem since they are really just a safety mechanism and it’s at this point that you’ll need a professional aircon servicing company’s assistance

Fuses react very quickly to a dangerous overload, causing overheating and, consequently, a blown fuse. They are important because they protect your sensitive electronic devices, like your aircon unit. This is why you’ll need to have a professional aircon servicing company get to the root of the aircon issue, prevent the cause of the overloads and save both yourself and your aircon unit from overheating especially during the hot summer days.

How can an aircon unit fuse can blow?

Any aircon repairs involving electricity should be undertaken with care. Electricity can be deadly. Before you work on any electrical components, make sure you’ve turned off the power to your aircon unit. Keep in mind that there may be two breakers, one for the inside, one for the outside.

Sometimes when a fuse blows, it’s because the condenser is working too hard from a dirty filter or dirty condenser coils. Cleaning and servicing these parts can be a DIY aircon repair or can be part of a regular maintenance plan from your heating and air company. 

Fuses can also just fail as they come to the end of their intended lifespan. Weather can also affect fuses in that very hot weather will tax your entire aircon unit and cause fuses to blow, or weather changes over time can expand and contract the wires, loosening them and causing a poor connection and a blown fuse.

If you’ve put in a clean filter, cleaned the condenser coils, tightened your wires, got new fuses and those also blow, you might have a bigger aircon issue that needs attention from a professional aircon servicing company.

How long do aircon unit fuses last?

The average life of an aircon unit fuse can last the life of your aircon unit. However, a number of underlying aircon issues with your aircon unit can speed up the rate at which the fuse wears down. If you notice that your aircon unit is experiencing electrical issues, don’t waste time trying to diagnose the exact aircon issue yourself, as this may lead to serious damage to your property as well as your entire aircon unit.

What causes them to blow?

There are many possible reasons for an aircon unit fuse to blow, and sometimes they are connected. Here is a list of some most common reasons:

1) Old or blocked motor

An old or blocked motor causes the capacitor to work over time. The capacitor is important because it helps run the cooling system, known as the condenser. This small part helps to regulate the electrical current as it flows through the condenser. Get a professional aircon servicing company’s opinion on whether or not the motor must be replaced. 

2) Dirty condenser coils

The coils on your aircon unit’s condenser can sometimes get dirty and the result is that, once again, the capacitor has to run overtime, ultimately blowing a fuse.

3) Clogged air filter

Similarly, when there is pressure on the condenser from either very extreme temperatures, a faulty motor, or dirty coils, the filter can then also get clogged and this will cause the machine to overheat and of course, the fuse doesn’t like this.

4) A malfunctioning compressor unit

Extremely hot weather can also cause other problems in your aircon unit. If the compressor is not working properly, the air is not being cooled enough. This could be because of too high levels of refrigerant in the aircon unit or as a result of frequently turning the machine off and then back on very quickly. 

5) Wear and tear on the fuse

The lifespan of a fuse can be up to 20 years. Aircon unit fuses are usually what is known as ‘slow-blow’ or ‘time delay’ fuses. This means that they are at work every time you turn the machine on and off and eventually, will simply wear out to the strain of the operation.

When to call for help?

If a fuse blows more than once, it may be more than just a routine failure or a momentary lack of maintenance. Other aircon issues that can cause the electrical portions of your entire aircon unit to blow fuses include an old or blocked motor, a malfunctioning compressor, low refrigerant, or a faulty condenser fan. All of these aircon issues cause your aircon unit to work harder, overtaxing the electrical and mechanical parts and triggering the fuse to work just as it should, keeping the rest of your entire aircon unit safe.

Multiple blown fuses or tripped breakers are never a good sign. Shut the system off and call a professional aircon servicing company right away.


It’s always a good time to talk about the common issues that aircon units have. This way, you’ll be able to spot if there are problems with your unit or not and prepare for its replacement accordingly. If you require our aircon servicing services, Whatsapp us at +65 9222 4141 for a fast and transparent quote.

338 Aircon Servicing Singapore provides an extensive range of Aircon Services including Aircon Servicing, Aircon Repairs, Aircon Installation of the best aircon brands, Chemical Overhaul, Gas Top-up, Aircon Leaking Water, and Aircon Not Cold Fix, and more. We have a team of professional technicians who are equipped with vast knowledge and experience in the Aircon industry. 

We have over 15 years of experience in dealing with aircon works and have completed thousands of aircon works for both residential (Landed, Condo, and HDB) and commercial. We are a highly recommended Aircon Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook.

WhatsApp us at +65 9222 4141 for a transparent quotation and honest pricing for all your aircon needs or Call us at +65 9222 4141. We offer a fast and efficient service to serve any of your aircon needs!  


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