Frequently Asked Questions

Boilers for home heating

Why should I service my boiler?

An annual boiler safety check and boiler service, carried out by a professional service engineer ensures that your boiler is functioning properly.  Regular servicing of your boiler is important as it ensures that the boiler is working to the specifications designed by the boiler manufacturer. This will help prolong the life of the boiler as well as reduce the risk of faults and expensive repairs down the line.

Who should I get to install my boiler?

Your boiler should be installed by a qualified and experienced boiler installer.  A good installer will be able to size your new boiler based on the actual heating requirements for your home. This will ensure that the boiler operates at its optimum capacity and be most cost effective.

How often should I service my boiler?

Most boiler manufacturers recommend an annual service, primarily on the grounds of safety but also to ensure reliability. On efficiency grounds it is well worth servicing oil boilers annually because soot build-up can significantly increase oil consumption.

Where can I find more information about the efficiency of boilers and where to purchase them?

The SEAI HARP (Home-heating Appliance Register of Performance) database maintains a list of all oil and gas boilers, and their efficiency, that are available on the Irish market. This list is available on the Sustainable Energy Authority’s website.

What is carbon monoxide?

Carbon monoxide (CO) is a highly poisonous gas. It has no colour, no smell and no taste and is often called the ‘silent killer’. When inhaled, it prevents blood from absorbing oxygen. At high levels it can kill in as little as 3 minutes; at lower levels it causes illness. It kills, on average, 6 people in Ireland every year and makes many more ill. CO can be produced by any fuel when burned – coal, turf, oil, gas, wood. It doesn’t just occur at home – in fact it can be produced anywhere that fuel is being burned: caravans, tents, mobile homes, boats, holiday homes, workplaces. For more information or general advice, visit or call 1850 79 79 79

How to protect yourself from carbon monoxide?

There are several ways you can proactively protect yourself and your family from carbon monoxide poisoning:

  • Ensure your appliances are correctly installed and SERVICED ANNUALLY
  • Ensure that rooms in your home containing heating appliances are properly ventilated – NEVER BLOCK VENTS
  • Make sure all chimneys are regularly swept and kept clear
  • Use appliances only for the PURPOSE for which they were designed, e.g. do not use a cooker to heat a room
  • NEVER use any appliance if you suspect it might be faulty
  • If undertaking ALTERATIONS to your home which may affect the safety or efficiency of your heating installation (e.g. adding an extension, converting a garage, removing internal walls, changing a living room into a bedroom, double glazing / weather sealed doors) follow this safety advice:
    • Do not block or build around any existing air vents or flues
    • If creating a new living space, ensure it has ventilation in accordance with Building Regulations
    • If adding additional radiators ensure that your boiler can cope with the additional capacity
    • If you are altering or adding appliances to a natural gas or LPG installation, ensure that work is carried out to IS813:2002 Domestic Gas Installations
  • Get professional advice on ventilation and flueing before embarking on alterations to your house.
  • Use Carbon Monoxide alarms but remember these are no substitute for regular inspection and maintenance of appliances, vents, flues and chimneys. Check that the Carbon Monoxide alarm complies with the EN 50291 standard.

For more information or general advice, visit or call 1850 79 79 79

Should I bleed my radiators?

Water based central heating systems only work if there is a minimal amount of air in the system. If the bottom of your radiator is warm but the top is still cold when the heating is turned on, it’s a sign that there is excess air in the system. Bleeding a cold radiator can help improve efficiency and reduce waste.

How do I bleed the radiators?

  • Locate your bleed key/screw driver and bleed valve.
  • Make sure the heating is turned off as to not introduce additional air into the system.
  • Make sure the intake and exit valves are open.
  • Place a cloth/kitchen towel under the valve.
  • Open the bleed valve. If there is air trapped in the system you will notice a hiss coming from the valve. This will continue until you get water coming from the opened valve.
  • Close the valve and repeat on any other radiators you have.
  • Check your boiler pressure levels to ensure that you haven’t affected the overall pressure within the heating system. If this is the first time you have had to do this you should consult the instruction guide as provided by the manufacturers.