What to Do When Your Fog Machine Is Not Working

You should never automatically work yourself into a frenzy and tank your party just because your fog machine is not working.  A critical skill in fog machine operation is staying calm and establishing the root cause of the machine stalling, if or when it does.

Often you will realize the machine is not broken, and it is something that you can fix yourself with basic knowhow of fog machine operation. Today we shall explore some of the most prominent troubles and show you how to go about restoring the functions of your stalled fog machine and when to seek expert intervention.

what to do fog machine not working

Insufficient Fog Fluid

Cultivate the habit of checking the levels in the tank regularly. It is referred to as fog juice because the fog is composed of it. The fluid is pushed through a heat exchanger, where it is vaporized to create the fog you see. The fog machine basically sprays tiny droplets of fog fluids in the air.

Modern fog machines have two popular types of fluid level management systems:

  • The first one features a fluid level indicator that displays the fluid level, keeping you alert, so you when to top it up.
  • The other is an auto-shutdown function that switches the machine off when it runs out of juice to protect it from resultant damages. It will overheat, and the heating element may crack, or the pump motor burns out if there is no fluid to pump.

The reason your fog machine is not producing fog could be as simple as you have run out of fog juice and/or the system has shut down after detecting insufficient levels because it was programmed to self-preserve.

It is among the first things you check, and when you discover the levels are low, ensure the machine is turned off, refill the tank, and it will be good to go. Also, check to ensure the fluid tube leading to the pump is not bent or kinked as this also chokes the fluid flow.

It is good practice to know the capacity of your fog machine and the fluid consumption rate. This gives you an idea of the kind of load it can push and for how long. Consequently, you can prepare for backup fog fluid, so you will seldom be caught unaware, and you can tell when there is a malfunction, or a leakage based on abnormal consumption.

If it still doesn’t work after confirming the fog fluid is sufficient, it’s time to amplify your troubleshooting.

Fog machines typically have two main components: a pump that pumps the fog juice through the machine and a heating element that heats up the fog fluid.

The Heating Element

Plug it in and give it time to warm up. A decent fog machine should not go beyond five minutes of just warm up time. If it warms up, that is enough confirmation that the heating element is working.

Caution! Don’t touch the nozzle to confirm the heat, or you may end up with third-degree burns. It gets really hot. Lightly feel the bottom of the unit.

If the machine is not warming up, test your power source to establish if you are getting the right amount of power.  If the power source is delivering, the issue may be with the wiring inside the fog machine.

We recommend you only open the fog machine if you are comfortable with electric circuits and there is no warranty violation to think about. Otherwise, take it to your service center or seek help from an expert.

We will get to troubleshooting an opened fog machine later, but we hope you won’t need to open it.

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Without a working heating element, the fog machine is incapacitated because fog cannot be created, and this heat triggers the pump to draw fog juice from the tank and push it through the heater.

If the heating element is damaged, you should consider getting a replacement fog machine because the cost of replacing a heating element often surpasses the cost of buying a new machine for most regular fog machines. It will only make sense if you have the expensive permanently installed units.


Fog fluid is technically not a lubricant, which means when you put your machine to storage, there are chances of corrosion and its resultant sediments. Additionally, little dirt particles get in through the fluid tank, especially if you are at a club or using the machine in dirty or dusty places.

These foreign particles are easily lodged in tight places in the fog machine by the moving fog fluid during normal operation. Eventually, they block these paths.

The Pump

The next step is to switch on the pump. You should hear the sound of the motor to confirm it is actually pumping. If it is pumping and nothing is coming out, there are high chances of a blockage somewhere between the pump, the heater, or their connecting channels.

The Heater

Sometimes the heater blocks, especially if you have been using cheap fog fluid or homemade liquid with tap water which tend to leave hard deposits. Make a point of using the recommended fog fluids to lengthen your wash cycles.

The smoke machine process is a form of distillation, so deposits like salt and minerals will form inside the smoke machine pipe, which is very thin, or on the outlets and valves where the fog fluid is meant to pass through.


  • Your fog machine is protected from deposits as it is specially formulated to vaporize neatly.
  • It is safe due to its composition of high-grade pharmaceutical ingredients.
  • It is usable with other water-based fog machines besides ADJ

Any blockage will restrict the flow of fog fluid, reducing or completely stopping the amount of fog emitted. The most reliable sign of blockage is the machine blowing out air without emitting any fog. This shows its components are working, but the fog fluid is not making it through.

The machine, therefore, needs to be flushed through to get rid of deposits and debris. This should be turned into a routine as a preventive measure to avert future occurrences.

There is a running debate on whether cleaning fog machines should be done with the more affordable distilled white vinegar or specially formulated fog machine cleaners. We shall shelve this discussion for another day as we are focused on a working solution today.


  • This formula has been designed to be used in all water-based machines to optimize their performance
  • It removes deposits that build up in the fog machine’s heater core, preventing it from clogging
  • Its safety rating is reliable as it has been made in the US with pharmaceutical-grade chemicals

Both options have their proponents and opponents, which means they have been known to successfully unclog fog machines. It boils down to personal preference.

Popping the Hood

Sometimes you need to take a closer look to establish the exact cause of your trouble. You may have figured out what is wrong and want to fix it, or the symptoms might be inconclusive, requiring more observation.

When opening up the machine, make sure it is turned off and unplugged.  A voltmeter will come in handy at this juncture to diagnose voltage issues and to check continuity, establishing how things are connected and where the gap is.

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Try this AstroAI Digital Multimeter, which is the complete package for diagnosing and resolving our electrical issues, even beyond fog machines.

  • It measures voltage, current resistance, continuity, and tests live wires
  • We feel safe when troubleshooting because it has a dual ceramic fuse if there is an overload and is easy to operate
  • The combination of a backlit LCD screen and data hold features also gives us time to record our readings to process the information later

Once the fog machine is open, you can begin by doing a quick visual inspection to see if anything is unplugged or unhooked.

The Thermocouple

When you switch on the machine, the power first goes to the heating element. There is a thermostat switch in this circuit that can sense the temperature of the heating element. When it feels the element is heated to its programmed temperature, it connects the pump. Enabling it to run.

One of the signs of a malfunctioning thermocouple is allowing the pump to work before the heating element is hot enough to produce fog. It will manifest in the form of the fog machine spitting out hot fluid instead of fog. This is a call to adjust the settings or replace them if you cannot adjust.

If you are not getting power to your heating element, the first place you should look is the thermostat switch. Make sure you are getting the full voltage from your power source to the switch. If you are not, there is a wiring issue, and you probably have to change the wires from the input to the switch.

If power is getting to the switch, check the voltage coming out of it and check the leads on the heater itself. If the voltage is getting to the heater and it is not heating up, it may have developed a crack or has an issue with the heating element. At this point, you have to decide between replacing the heater or getting a new fog machine.

Inspecting the Pump

When you press the pump button on, you may hear a humming sound, yet nothing happens. In some cases, even the humming will not be heard. The humming with nothing else means the rotor is working, but there is a clog somewhere along the line, or there is a mechanical issue within the pump.

Remove the pump because it is easier to test and clean it in isolation. This way, you can also narrow down on whether the problem is in the pump.

Disconnect it from the fluid reservoir and the line that transmits the fluid to the heater. Test the pump and the line separately to ascertain if there is a clog and exactly where it is.

The line can be cleaned easily with your preferred cleaning agent and tested to see if the fluid flows from one end to the other.

On the other hand, the pump may be clean but has a failed component that is preventing it from pushing the fog fluid to the heater. Connect it to a power source and see how it behaves on its own.

Check if the seals are still tight; if they are compromised, air will get into the pump, reducing the pressure and, by extension, the pump and fog delivery force.

The same seals may also be responsible for preventing the pump pistons from pushing the fog fluid out if they become too tight. There are valve springs that hold the valve shut, ensuring the fluid only flows in one direction. If the seals are too tight, they will overpower the springs to the extent that the pump is no longer pushing fluid.

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The pump might be working, yet the valves or the springs are worn out, so they can’t exert the pressure needed to push the fog fluid towards the heating element.

You can get a replacement pump or try and repair the existing one if you can find the right parts.

Inspecting the Electrical Panel

Sometimes all the components of the fog machine will be working fine, yet the power is still not getting to the pump. It can be a blown relay or fuse from the low fluid indicator or the auto-shutdown system.

They are meant to disconnect power when certain limits are exceeded, but they become permanent circuit breakers when they are blown. Blown fuses should be replaced with others of similar ratings. Circuit breakers should also be reset at this juncture.

When the Fog Machine Makes a Loud Noise

This scares the bejeesus out of you and your small kids every time you switch it on. As much as that is the whole point of Halloween, it could be a sign of something wrong. The noise may either be due to the dispersion of fog from the unit or emanating from the pump itself.

If it is from the dispersion of fog, that is a normal trait in a number of fog machines, and you should not be alarmed. This sound is the vapor coming out of the fog machine with force, especially for higher wattage models with great output distances.

It will most likely be in the form of a loud hissing sound. Different machines produce different sounds; upshot foggers will generally be louder than low-lying fog machines because they need more force to blow the vapor upwards.

Their sound is also projected upwards. The noise will be different if the pump is failing. It will be combined with a chunking sound and most likely other telltale signs like a drastic drop in fog emission or a complete lack of it. Be careful when fixing a failing pump, as it could void your warranty or make the situation worse.

Sometimes it calls for a chat with the manufacturer or the nearest service center. If it is just a case of a loud machine, you can try placing it further away from where the action is, blocking it with decoration, or even building a containment unit for it. Whatever you decide to do, ensure the nozzle path as clear as it gets extremely hot.

Pro-Tip: Turning the other sound effects a few notches higher can significantly drown the loud hissing of the machine, making it impossible to hear unless you are standing right next to it.

Making the Fog Machine Work

There is always the risk of an unanticipated occurrence which we may not have covered in this summarized guide. Fog machines are coming up every day with more advanced technology.

The trick is knowing the limits of your particular fog machine and reducing the odds of being surprised when something happens.

Below some important figures you should have on your fingertips:

  • The fluid tank capacity for estimating how much fog fluid you have to work with.
  • The fluid consumption rate helps you estimate how much time you have left, given the current fluid situation.
  • The backup fluid quantity estimates how much longer you can sustain the fog machine once whatever is in the tank gets used up.