Boiler

A gas boiler uses gas as a fuel. Depending on their installation, gas boilers can be free-standing, whose heating value is higher, or wall-mounted, which are usually installed in the kitchen or bathroom.

Gas boilers can be used for heating only, or for heating and generating domestic hot water.

Depending on their operation, performance and consumption, there are different types of boilers:

• Standard boilers: traditional operation boilers. Their performance is lower, since they need to consume more energy in order to heat the water.
• Condensing boilers: These are high-performance boilers that use the water steam produced in the combustion gases. Compared to conventional units, condensing boilers save energy and reduce carbon dioxide and nitrogen oxide emissions.
• Low-temperature boilers: These can operate continuously with a return water (not boiler) temperature below 40ºC. Their performance is lower compared to condensing boilers, but higher than in the case of standard units.

Depending on where the air used for combustion comes from, there are atmospheric gas boilers (it comes from the same room where the boiler is located) or airtight (they take the air from the outside). Airtight boilers are safer.

Definition and types od heater

Installations with gas heaters can supply domestic hot water. The heater generates hot water which is taken through the plumbing installation to any of the supply points available in the installation, whether taps or domestic appliances.

There are two types of basic heaters, open circuit and airtight

• Open circuit: they take the air needed for gas combustion from the room where they are installed and expel the gases outside through the exhaust pipe.
• Airtight: the air coming in and the discharged combustion gases do not come into contact with the room there the heater is installed.

Ventilation grille

• Remember: you must not cover or block the ventilation in the room where the boiler/heater is located.
• Ventilation grilles must be in perfect working order. Do not block them.
• If you glaze the terrace or drying place, don't forget to open the ventilation grilles.
• The gas exhaust pipe is essential to guarantee proper operation of the appliances. Ask a specialist to install one according to regulations.

Iberdrola helps you keep your gas installation safe

General recommendations

Some elements or devices can enhance the safety of your gas installation, for instance:

• Replacing the flexible rubber pipe with a safety pipe.
• Gas stoves with burners that detect when the flame goes out.
• Ambient CO detectors and gas detectors.
• Installation of airtight boilers in areas with poor ventilation, instead of open-circuit boilers.
• Avoid using simultaneously the extractor fan and the open-circuit water heater or boiler.

Maintenance

• Remember that, according to law, you must have your gas installation checked regularly and keep it in perfect working order. Sign up for Iberdrola's Gas Maintenance Service.
• The distribution company is required to check your natural gas installation every five years (four in the Basque Country)./li>
• The gas installation can only be handled or maintained by authorised professionals.
• In case of any doubt, please contact your service technician or gas company immediately.

Ventilation

• Water heaters and boilers need an efficient smoke venting.
• Good ventilation is essential: keep all ventilation grilles in perfect condition and never obstruct them.
• The gas outlet pipe must also be in perfect condition.
• You must pay special attention to the flame you see. It should be stable, silent, blue in its core and lighter on the outside. If this is not so, please have the installation checked.
• Be careful that the flame is not blown out accidentally; gas could be escaping without your realising.
• If you are going on holiday or are going to be away for some time, switch off the main gas tap.

If you smell gas

• Do not switch on lights or any electrical appliance; they may give off a spark which could cause fire or an explosion. Neither should you use a lighter, matches or anything which could cause a flame.
• Open doors and windows in order to ventilate the area.
• Switch off the appliance as well as the main gas tap and, if necessary, call the emergency service to check the installation.