Useful Information on Natural Gas


A natural solution to energy needs

Natural gas is classified as a ‘fossil fuel’. It is an energy source provided by nature itself, with no need for further processing and is, therefore, preferable to other sources that require expensive and complex production processes before they can be utilised. It is a natural solution to every family and every home’s need for ease and comfort.

Natural gas saves energy spent on cooking, produces hot water on demand without any waste, and heats the house whenever and however needed. A few simple measures are all that is needed to use natural gas in complete safety.

Information, clarifications and tips on the efficient use of gas at home are provided hereafter.

It is easy-to-use and versatile

Natural gas will meet all your domestic needs, from cooking and hot water to heating. Recent technology has also made it possible to use gas for air conditioning in the summer.

It is abundant

Global natural gas reserves are huge and sufficient to meet long-term energy needs.

It is convenient

Natural gas means it is no longer necessary to buy and store fuel. You will only have to open the valve and there will be gas energy available, ready to use. You will only have to pay for the volume of gas used, only after you have used it, and it will be easy for you to check gas consumption by just reading your meter.

It is a fuel with low environmental impact

Natural gas is distributed via special pipelines, in the same form it is extracted from natural underground reservoirs, without any intermediate processing between extraction and consumption. Natural gas is highly energy-efficient and has limited environmental impact, as its combustion leaves no traces or residue and it does not produce sulphur compounds - one of the principal causes of pollution.

It is safe

Natural gas contains no toxic substances. In its natural form, it is colorless and odorless. Its odor is added during distribution, to allow people to identify even the slightest leakage. You can have gas installed at home quickly and easily, always in accordance with the regulations in force, by properly trained, legally authorized staff.

Natural gas at home guarantees safety

When properly used, natural gas ensures the maximum possible level of safety. You only have to comply with applicable conditions and rules.

Proper installation

An internal natural gas installation consists of a set of pipes, fixtures, appliances and devices (stove, burner, boiler, etc.), installed after the delivery point (gas meter) through vents in the areas where gas devices are installed, and up to the exhaust flue of the installation. To make sure that gas installations are totally safe, stringent installation requirements have been established, and installers are required by law to comply with them. These requirements are laid down in the Technical Regulation for Gas Installations with an operating pressure of up to 500 mbar, Ministerial Decision No Δ3/Α/οικ. 6598, (OGG, Series II, No 976/28.03.2012)

The European quality mark

Gas devices fall within the scope of Directive 2009/142/EC relating to appliances burning gaseous fuels and must have the CE marking affixed to them or on their label (the CE marking guarantees that the device meets the safety standards) and must also be suitable for the country of destination (Greece). This means that the Greek installation and connection rules have been observed and there are instructions for use and installation provided in Greek, conforming to the Greek installation requirements.


Domestic uses

Individual heating - Hot water

Individual boilers will meet the needs of an apartment for heating, or both heating and hot water.

Where used for heating, the device is connected to the plumbing installation of the apartment or single-family home, i.e. the water pipes used to supply the radiators. Where used for hot water, the device is connected to the hot water supply pipes in the kitchen and/or bathroom.

Individual, mostly wall-mounted, but also floor-mounted boilers are available on the market.

Individual wall-mounted boilers are typically installed in the kitchen or bathroom or on a balcony. Depending on the combustion air input and the type of flue, the boilers are classified as open or closed type.

Open-type boilers obtain air for combustion from the indoor area in which they are installed, and the gases are vented through an exhaust (the installation area must be properly ventilated), whereas closed-type boilers obtain combustion air from the outdoor environment.

Tankless/storage water heaters

Tankless water heaters are gas devices in which the gas burner functions only when hot water is needed (5 to 18 l/min).

Storage water heaters are preferable where large amounts of hot water are needed. They can store from 40 to 300 l of hot water.


There are stoves available in the market, where both the burners and the oven are gas fired. There are also hybrid stoves, where some of the hot plates or the oven work by electricity.

Stoves are typically fitted with an automatic ignition system and must be provided with a flame supervision device (FSD), that blocks the flow of gas when there is no flame (thermocouple). Their installation and space requirements vary depending on the capacity of the device, according to the provisions of the Regulation.

Central heating

In most cases, replacing the burner is the only modification needed to use natural gas for central heating purposes. A boiler-burner system that heats water, is installed in the building’s boiler room. The hot water will then circulate through the radiators. If the boiler is too old, it must be replaced to achieve a higher efficiency rate. A central heating boiler can be combined with a hot water boiler.

Burners are classified as single-stage, two-stage, three-stage burners based on the mode of operation used (functioning at one or several capacity levels). They are also classified as atmospheric or pressure burners based on the gas pressure in the combustion chamber.

Space ventilation

All fuels require a certain amount of oxygen to burn. It is, therefore, important that the areas in which the devices are installed are of the right size, constantly ventilated (depending on the type and capacity of the device) and provided with suitable flues for exhaust gases, always in accordance with the provisions laid down in the Technical Regulation.

Exhaust gas venting

The product of the combustion of natural gas is vented into the outdoor environment. This is done through specific exhausts (depending on the type of device used), in accordance with the legislation in force.

It is important to regularly check the condition and effectiveness of the exhaust gas venting system to make sure that it is not blocked by bird nests or other objects. The devices currently available on the market are even safer, as they are fitted with a shutoff system that is triggered in case exhaust gas flows back into the indoor area. All the details on the exhaust gas venting system are included in the current Technical Regulation, with which the gas supervisor and installer must comply.



Regular maintenance: a short useful appointment

Inspection: the right habit

The safety of a gas installation depends on proper functioning, proper handling, regular inspection and scheduled (preventive) maintenance carried out in accordance with the operating and maintenance schedule and the up-to-date gas installation file.

The consumer is only able to ‘inspect the installation’ and should have the devices and piping regularly maintained.

Regular maintenance of gas devices, burner adjustment, boiler cleaning and overall installation inspection will ensure energy savings, optimal efficiency and safety. It is very important to carefully clean the burner (and the heat exchanger) and possibly adjust it, to ensure proper combustion (when the flame is not bright blue, but there are persistent yellow tongues of fire). It is also important to verify the effectiveness and proper functioning of the adjustment, safety and control systems/devices, as well as the effectiveness of the ventilation system used in the area where the devices are installed, and of the exhaust gas venting system.

The Technical Regulation also provides for the tightness of the installation piping to be inspected every 4 years by an authorised installer, who should take measures as appropriate, and an inspection certificate to be obtained from the Company.

In addition to that, the exhaust gas must be tested to determine the boiler’s efficiency and the maximum exhaust gas values laid down by law at the frequency of testing specified by the  OGG No 2654/09.11.2011 regulating matters relating to the functioning of stationary combustion units used for building and water heating purposes.

The technician should record the test and analysis results in the installation logbook, which must be kept in the installation area, in accordance with the operating and maintenance schedule.

It may seem obvious, but the most important thing you should do if you smell gas is….. to be careful. Certainly, there are certain simple rules to keep in mind.


Steps to be taken in case of malfunction or smell of gas

Key principles

Any smell of gas should be reported to the Company. Make a toll-free call to 10302 from a landline phone or call 2310 520309 or 2310 520642 from a landline or cell phone. In the event of any other failures or malfunctions, you should notify a technician or in some cases the Company.


Steps to be taken in case of gas smell in a building

  • Open the doors and windows wide, make sure that there is flow of air and avoid any areas where there is a smell of gas!
  • Do not light a fire, avoid flames, do not smoke and do not use a lighter!
  • Do not use electric switches, sockets, electric bells, telephones or other communication devices in the house!
  • Close the main valve!
  • Notify the EMERGENCY SERVICE of the Company by calling from outside the house!


Steps to be taken in case of gas smell outdoors

  • Notify the Immediate Intervention Service of the Company.
  • If the smell of gas can be attributed to a leak in an underground outdoor pipeline (e.g. pipeline in the yard, supplying the inside of a building), the pipeline must be blocked using the shutoff valve.
  • Close the doors and windows of nearby buildings!
  • Avoid flames, do not smoke and do not use a lighter!
  • Do not use electric switches, sockets or electric bells!
  • Notify the tenants of the house, but do not use electric bells!


Steps to be taken in case of gas leakage from gas devices

  • In case of gas leakage, the gas device must be switched off by closing its valve and the maintenance expert, or even the distribution company, must be notified.


The staff of the Company: identifiable guarantee providers

All the employees and officials of the Company hold a special ID card, which you are entitled to check at any time.

The employees and officials of the Company are not authorised to receive payments at someone’s home.

The Company is not responsible for internal installations, does not sell devices, nor does it grant licenses to sell devices, mechanisms or other goods from door to door.

Except from emergencies, interventions to modify or maintain gas meters or installations falling under the responsibility of the Company are carried out following telephone or written notification or after arranging an appointment.

The Company kindly asks you to report any ‘suspicious’ incidents or visits, so that appropriate action can be taken, either by declaring them at the Customer Service Offices at:

  • 256 Monastiriou St & 7 D. Glinou St, 54628 Thessaloniki, Fax: 2310 500577
  • 219 Farsalon St, Giannouli, 41335 Larisa, Fax: 2410 552550
  • 32 G. Kartali St, Agria, 38333 Nea Ionia, Volos, Fax: 24210 76264 
  • 18 Taliadourou St, 43100 Karditsa, Fax: 24410 23010
  • 33 Syngrou St, 42100 Trikala 


or by calling 11150 (Monday - Friday: 08:00 to 20:00, Saturday: 09:00 to 15:00)


A natural solution even to safety issues