Last updated: August 10, 2021

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Gas detectors are lifesavers. Time and again, we hear about gas explosions and deaths from suffocation due to gas accidents. That's exactly what you can protect yourself against with gas detectors. They measure the gas content in the air and warn you in good time before the value becomes too high so that you can take countermeasures in good time. Depending on the device, you are not only protected when you heat or cook with gas, but also from carbon monoxide, which is produced during an incomplete combustion process.

In our big gas detector test 2021 we show you what you should look for when buying such a device and help you to make the best possible decision. Here you can find out which gases you should protect yourself from, what types of gas detectors there are and what you should do if your device sounds the alarm.


  • Gas detectors measure the level of explosive gases and mixed gases in the air and sound the alarm if it is too high, so you can react in time before it is too late
  • Gas detectors can mainly detect and warn about 4 different types of gases. These are: Carbon monoxide, natural gas, liquid gas and narcotic gas
  • For permanent protection against gases, a stationary gas detector is suitable, as it measures the gas content in the air at all times

The Best Gas Detector: Our Picks

Guide: Questions you should ask yourself before buying a gas detector

Why do you need a gas detector?

Many gases are odourless and invisible, so you cannot detect them without a gas detector.

Gas detectors warn you of possible gas explosions.

Gas detectors measure the level of explosive gases and mixed gases in the air and sound the alarm early so that you notice in good time if you have a gas leak in your motorhome or home. This way you can act immediately before a gas explosion or carbon monoxide poisoning occurs.

Such gas alarms are especially useful for people who use a cooker with a gas hob or use a gas cooker when travelling.


Whether for camping or in the home - gas detectors offer reliable protection against gas explosions
(Image source: Crumper)

Are gas detectors compulsory?

In Germany, gas detectors, as well as fire detectors, are not compulsory, unlike smoke detectors. So you can decide for yourself whether you want to get one.

However, in many households or when camping, it makes sense to get a gas detector, as most gases are colourless and odourless and are therefore only noticed much too late.

At night, our sense of smell is switched off, which is why escaping gases go unnoticed, especially at night.

In flats and houses with gas heating systems, gas ovens, gas heaters, gas cookers or gas fireplaces, it makes a lot of sense to think about getting a warning device. But a gas detector is also recommended for mobile homes, where a lot of gas is used.

Carbon monoxide can develop wherever combustion with gas, coal, oil, petrol or wood takes place. Therefore, a CO alarm is worthwhile even if you do not use gas in your home. Possible sources of danger for the development of carbon monoxide are, for example, oil or wood stoves, fireplaces, open fireplaces or cars in closed garages.


Gas cookers are not only practical everyday helpers, but also a dangerous threat if there is a leak in the gas pipe.
(Image source: Ferlič)

What does a gas detector cost?

Simple gas detectors are available from about 25 €. If you are looking for a carbon monoxide detector, you will find products starting at 15 €.

However, keep in mind that a gas detector can save lives in an emergency. Therefore, it is recommended that you dig a little deeper into your pocket and not go straight for the cheapest product. Many experts recommend spending between €50 and €100 to get higher quality and safer products.

Type Price range
Carbon monoxide detector 15-60 €
Gas detector 25-200 €

How long do gas detectors last?

Unfortunately, gas detectors only have a limited lifespan because the sensor built into the device is very sensitive and wears out over time. Gas detectors last about 5-10 years, but you should pay attention to the manufacturer's exact specifications as to when your device needs to be serviced or replaced.

Also note that some gas detectors are battery operated. This may need to be replaced beforehand. With a permanently installed battery or a device with a mains connection, you can of course save yourself the trouble.

Decision: What types of gas detectors are there and which is the right one for you?

If you want to get a gas detector, you can choose between two options:

  • Stationary gas detector
  • Portable gas detector

One type is not fundamentally worse than the other, it just depends on what you need and what suits you and your requirements better. We have listed the advantages and disadvantages of these options below to help you decide what to buy.

What distinguishes a stationary gas detector and what are its advantages and disadvantages?

Stationary gas detectors are permanently installed in your flat or house by screwing them onto the ceiling or wall.

  • Permanent measurement
  • Usually cheaper (compared to mobile gas detectors)
  • Permanently installed in the home
  • Several devices required for the entire home
  • Permanent power consumption/battery wear

Since stationary gas detectors permanently measure the gas content in the room, you are always safe from possible gas leaks. As soon as a certain value of gas content in the air is exceeded, the alarm sounds and you can take protective measures. Stationary gas detectors are usually cheaper than mobile gas detectors.

Stationary gas detectors are permanently installed in the home, which is why you can only use one device in a room at a time. Therefore, you may have to buy several gas detectors for your home. Also, don't forget that stationary gas detectors are permanently connected to the mains and also draw electricity all the time.

What are the features of a portable gas detector and what are its advantages and disadvantages?

You can always take portable gas detectors with you and use them in all areas of your flat or house.

  • Can be taken anywhere
  • Only one device needed
  • Less electricity costs/batteries needed
  • Measures only at the push of a button
  • Usually more expensive (compared to stationary gas detectors)

Mobile gas detectors can be used in all rooms of your house. Therefore, in contrast to stationary gas detectors, you only need one device to test the gas level in all areas of your home. In addition, electricity costs are lower and batteries need to be changed less often, because mobile devices only measure at the push of a button and not permanently.

However, this does not guarantee permanent protection, as you have to actively check yourself whether the gas content in the air is too high. This is particularly dangerous in the case of odourless gases, which you would not even notice without measuring them. Compared to stationary gas detectors, the portable alternatives are often more expensive to buy.

Buying criteria: You can compare and evaluate gas detectors based on these factors

Even if it doesn't seem like it at first, there are a few things you should consider and think about before buying a gas detector. The criteria you can use to compare gas detectors with each other are:

In the following paragraphs, we will explain what exactly you need to consider in the individual aspects:

Types of gas

Knowing which gases your gas detector detects is important so that you know what you are protected against and where exactly you have to install your device.

Gas detectors can alert you to these gases:

  • Carbon monoxide
  • Natural gas (methane)
  • Liquid gas
  • Anaesthetic gas (knockout gas)

Carbon monoxide can occur in any home, even if gas is not used. Nevertheless, CO detectors are found in very few German households. Carbon monoxide is a colourless and odourless gas that is produced by incomplete combustion and causes suffocation if the amount of gas in the room is too high. A carbon monoxide detector is recommended if you have a stove or fireplace or park your car in a closed garage.


If the chimney has not been cleaned properly, carbon monoxide can be produced in the fireplace.
(Image source: Lyashenko)

Natural gas is also colourless and odourless in its pure form, but for home use it is mixed with strong-smelling fragrances that you notice escaping methane. Despite this, your sense of smell is switched off while you sleep. This is highly dangerous, because natural gas is highly explosive, and if gas escapes, explosions can occur quickly. So if you heat or cook with natural gas, you should get a gas detector that warns you of methane so that you are safe at night.

Liquid gases include butane and propane, which are mainly used for camping or sometimes for heating. They are also odourless. This means that in the event of a gas leak, the gas can flow out unhindered. There is a danger of explosion and suffocation. Liquid gas detectors are therefore best suited for you if you want to install the gas detector in your caravan or if you heat your home with propane.

Among campers, there are often reports of raids with anaesthetic gas. This involves sneaking narcotic gas into the camper and then robbing the camper while they are unconscious. So if you like camping, you should also look at narcotic gas or knockout detectors.

use-of gas danger
Stoves, car in closed garage, fireplace carbon monoxide (CO) asphyxiation hazard
Gas heating, gas cooker (natural gas operated) natural gas (methane), town gas explosion hazard
Gas heating (liquid gas operated) liquid gases (butane, propane) risk of explosion
Caravan, camper anaesthetic gas (KO gas) unconsciousness

Type of warning signal

How your gas detector should alert you to the presence of too much gas in the room in an emergency is also important to decide beforehand.

This is often done by a loud warning signal. This should be between 75 and 80 decibels loud so that you can hear it throughout the house, no matter where you are. There are also differences in the sounds the device makes. Most beep very loudly, but newer ones can also speak and explain exactly in which room the gas level is too high.

In addition, some devices also warn you of the gases with a flashing light. As a rule, a green light means that everything is OK. A red flashing light is the warning signal.

Another option offered by the gas detector market are gas detectors that are connected to each other via WLAN and send a message to your mobile phone in the event of an alarm. This way, you know what's going on even if you're not at home.

Connection type

The type of connection is also a decisive purchase criterion. Depending on where you want to use your gas detector, different types make sense.

Gas detectors can be operated by mains connection, battery or rechargeable battery.

Most gas detectors have a mains connection. This means that you always need a power socket in the right place. As we have already described with the types of gas, you need to consider where you place the device so that it can function in the best possible way. So if you don't have a socket within reach, this option is obviously not for you.

Some manufacturers install a rechargeable battery or a battery compartment in addition to the normal mains operation. This ensures that the gas detector can reliably warn of possible gases even in the event of a power failure. If you have a power socket in the best places in the room and want to be on the safe side, this is an optimal solution.

As an alternative to these options, there are also gas detectors that are powered exclusively by batteries. This is particularly practical if, as described above, you don't have a socket in the right place or if you don't have a socket in your caravan because they are all needed elsewhere.


Gas detectors have very sensitive sensors that wear out over time. Therefore, you must replace the warning devices occasionally.

Before buying, it is therefore important to check how long the manufacturer guarantees the lifetime of the warning device. It is worthwhile to buy a longer-lasting product to avoid having to search again after a short time.

Some devices are battery-operated instead of being connected to the mains. This is often included with the purchase. In this case, you should also pay attention to the specified battery life.

Facts worth knowing about the topic of gas detectors

Where are gas detectors installed?

The best place to install your gas detector depends on the gases you want it to warn you about. Different gases have different densities, so some of them are lighter or heavier than air and tend to sink or rise accordingly.

In the following, we have explained where the different detectors should best be installed:

CO detector
If you install your carbon monoxide detector in a room with a burning place (fireplace, gas cooker, garage...) you should mount it on the ceiling. Just make sure that you install it at least 30 cm away from the wall and 1-3 m away from the source of the fire.

In rooms without a fireplace, the CO detector is mounted at breathing height. However, make sure that you mount the detector in the bedroom at the same height as your head when you are lying down.

Methane detector
Natural gas or methane detectors are best installed on the ceiling above the possible leakage point or on the wall as close to the ceiling as possible. The detector should not be higher than 4 metres at any point and should not be more than 8 metres away from the possible leakage point.

Note: In the case of sloping roofs, the detector should be mounted on the ceiling about 30 cm from the highest point in the room.

Liquid gas detector
Liquid gas is lighter than air and therefore sinks downwards. For this reason, your gas detector should also be installed approx. 30 cm above the floor and no further than 4 m from the possible point of leakage.

Gas mounting
Carbon monoxide (CO) ceiling or breathing height
Natural gas (methane), town gas ceiling
Liquid gases (butane, propane) 30 cm above the floor

What you should also pay attention to so that your gas detector does not sound a false alarm or go off too late:

  • Do not install directly next to doors or windows
  • Do not mount it next to extractor bonnets or ventilation systems
  • Do not mount it above cookers or other heat sources
  • Do not install behind furniture or curtains
  • Areas with high dust generation (e.g. workshops) are unsuitable
  • Not directly next to a gas source

What to do if the gas detector goes off?

If your gas detector goes off, you should follow these steps:

  1. Stay calm: In any case, stay calm and do not panic.
  2. No electrical appliances: Do not use any electrical appliances and do not switch on the light! Any small spark can cause an explosion.
  3. Open windows: Next, open some windows to allow the gas to escape.
  4. Close the main gas tap: If possible, close the main gas tap so that no more gas can flow in.
  5. Leave the house: Then leave the house quickly (if you live in a block of flats, you should inform your neighbours so that they also leave the house)
  6. Call the fire brigade and the fault clearance service: At the latest when everyone has left the house, inform the fire brigade and/or the fault clearance service of your gas supplier about the incident

What to do if the gas detector gives a false alarm?

If your gas detector beeps and you suspect a false alarm, you should act as you would in an emergency.

If you have followed the installation instructions carefully, false alarms are very unlikely. So if the gas detector goes off, proceed exactly as you would in an emergency, even if you suspect a false alarm. If it turns out that the alarm system has given a false alarm, you will not have to pay the costs of the fire brigade or the emergency services, because the emergency call is justified. So it's better to be safe than to misjudge the situation.

Maintaining gas detectors correctly

To be sure that your gas detector will continue to work properly for several years, you should test it every month to see if everything is still working properly. To do this, simply press the test button on your detector. It will then sound an alarm to show that everything is still working properly. Many of the devices also have a small light to indicate that the gas detector is working properly.

Also make sure that you wipe your gas detector with a damp cloth once or twice a month. Otherwise, dust and dirt can affect the sensor's measurements.

Image source: Polsawat/

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