Central heating and boilers

The current lifespan of boilers is around 12 years. From 2005 any new gas boilers installed had to be high efficiency condensing boilers. And since October 2010 any new boilers installed must be A-rated, or 88% efficient. In exceptional circumstances, non-condensing boilers can be installed if necessary.

• Condensing boilers get their name because they enter what is called “condensing mode” at regular intervals.
• They start to extract heat from the exhaust gases that would otherwise escape through the flue, in the process turning water vapour from the gas back into liquid water or condensate.
• A condensing boiler captures much more usable heat from its fuel than a non-condensing boiler.
• A condensing boiler can be up to 12% more efficient than non-condensing boiler as it utilises the “latent heat” that is released from the burned fuel as it changes from vapour into water
• The heat exchanger makes sure that as much heat as possible is transferred from the boilers’ burner – and as little as possible is lost in gases through the flue.

• ‘Combination’ (or combi)
• ‘System’ or ‘Open Vent’

Combination or Combi condensing boilers provide heated water for radiators or under floor heating. And give you instant hot water without the need for a hot water cylinder.

System or Open Vent condensing boilers also provide heated water for radiators or under floor heating, and require a hot water tank where hot water is heated and stored.

The type of boiler you chose to have will depend on the suitability of each, and your lifestyle or needs. Not all new boilers have to come without a hot water tank, although they do have to be condensing, in the majority of situations.

Combination/Combi condensing boilers
These heat water for the taps when you turn the tap on, so you don’t need to set a timer to warm water before it can be used.

• No need to have a separate hot water tank, so can be space saving.
• No heat loss from a hot water tank as it only heats water on demand.
• This is ideal if you don’t use much hot water each day.

A combi condensing boiler may not be suitable when:

• The house has low mains pressure.
• The house has multiple bathrooms or shower (that isn’t electric)

System or Open Vent condensing boiler
Can store hot water in a separate tank, so large amounts of hot water is available if multiple points/taps are in use at one time, this ideal if you like to use an airing cupboard.

Boiler replacement could be simpler if replacing a like for like system, as not all home heating systems will be compatible with a combination boiler.

We can tell you which type of condensing boiler – regular or combination – is most suitable for your home. Just give us a ring 0800 488 0112.

If your boiler is 15 years old or more then it is likely to be a G-rated boiler. Replacing an old G-rated boiler with a new A- rated condensing boiler, and a full set of heating controls, can save up to a quarter on your heating bills straight away and up to 1,200kg of CO2 per year.

To tell a condensing boiler from a non-condensing boiler, look at the flue that sticks out from the outdoor wall adjacent to your boiler.

A flue is a pipe that takes the exhaust gases generated by your boiler and passes them out through the wall or roof – letting them escape into the air. A piece of metal covers the end of the flue or plastic, which makes sure that a good flow of air is maintained.

• If the flue is made of plastic and lets out visible steam when the boiler is firing, then congratulations – you are likely to have a condensing boiler already.
• If the flue is made of metal and no steam is visible, you are likely to have a non-condensing boiler. These older boilers let out much hotter gases that are invisible to the naked eye – and would melt a plastic flue.

Boilers are rated according to their efficiency in converting fuel to heat as a percentage. This rating is called SEDBUK – Seasonal Efficiency of Domestic Boilers in the UK.

There are two (2) SEDBUK rating systems, SEDBUK 2005 and the newly updated SEDBUK 2009. SEDBUK 2005 uses an A to G rating, A-rated boilers being more than 90% efficient. SEDBUK 2009 no longer uses the A-G rating but only displays the percentage efficiency. Under the new system a SEDBUK 2005 90% efficient A-rated boiler will be regarded as 88% efficient, according to SEDBUK 2009. This goes for gas, oil and LGP boilers. The 2% difference between SEDBUK 2005 and 2009 is mainly down to differences in efficiencies between using a boiler for space heating in the winter months and only using it for water heating in the summer months.

The A-G rating will still apply if the boiler was tested under SEDBUK 2005, and should be made clear under what test standards the boiler was tested. There are new minimum efficiencies for gas, oil & LPG replacement boilers in Great Britain.

*Only A-rated boilers – rated at 90% or better – carry the Energy Saving Trust Recommended logo.

When your new boiler is being installed or serviced, we will also usually clean and flush your central heating system, and add a chemical inhibitor that helps to reduce lime scaling and corrosion. This will remove any lime scale or sludge already in your heating system – ensuring your heating continues to work as efficiently as possible. There are three main treatments that can be used:

• Flushing: This will either involve a `power flush’, or ‘mains pressure water flush’ (which will take longer).
• Inhibitors: Chemical inhibitors can be added to the system, helping prevent build-up of lime scale and help prevent corrosion.
• Water softeners: If a combination boiler is installed in a hard water area, water softeners can be added to the system.

Power flushing is the most thorough and effective way to cleanse existing systems and hot flushing is more effective than cold flushing. But the method we use depends on your make of boiler, as does the type of cleanse we user.

Any maintenance work on your boiler in years to come should also be carried out by a Gas Safe installer, such as Green Deal Solutions. We will also be able to tell you when you need to get your boiler serviced.

A system may benefit from cleaning:

• If a system is `cold-spotting’ – where the radiators do not provide uniform heat and feel cold to the touch in patches.
• When the system pump can be heard `labouring’ – because the system is pumping round not just water, but also the build-up of sludge or lime scale.

You can contact us on FREEPHONE 0800 488 0112 or enquire via our online contact form. We’ll be able to advise you through getting a new energy efficient system.