| What is a condensing boiler? | | | | What are the Cons of installing a condensing |
| A condensing boileris a boiler that employs a more | | | | boiler? |
| efficient method of extracting heat from | | | | - Some models have been known to generate as |
| combustible fuel than a traditional oil or gas fired | | | | much noise on start-up as a jet engine taking off! |
| boiler. A great deal of heat is wasted in a normal | | | | - They tend to be more expensive to buy than |
| non-condensing gas or oil boiler in the form of hot | | | | non-condensing models, anywhere from |
| flue gases that escape up the flue vent. This gas | | | | £100-300. |
| will be at a temperature of about 180°C. | | | | - They produce a visible plume of steam when |
| A condensing combi boiler is designed to permit | | | | they are operating. |
| these gases to rise as in a standard boiler but at | | | | - The condensing boiler flue terminal needs to be |
| the top the gases are redirected towards and | | | | sited carefully to avoid creating a nuisance for |
| cycled around a secondary heat exchanger, which | | | | neighbours. |
| draws heat from them, leaving them at a | | | | - The process of condensation produces an acidic |
| temperature of approximately 60°C. Some | | | | liquid that must be plumbed into a suitable waste |
| condensing boilers even have dual heat | | | | pipe or drain. |
| exchangers, to extract even more heat from | | | | - They need an advanced heating control system |
| these waste gases. | | | | in place to operate at max efficiency. |
| This heat extraction and subsequent loss of | | | | - The home needs to be well insulated or the |
| temperature causes much of this gas to | | | | extra heat that a condenser boiler generates will |
| condense into water vapour, which then falls to | | | | be lost through the walls and ceiling. |
| the bottom of the flue, where it is channelled | | | | - Central heating condensing boilers need an |
| either into a pipe leading to the household soil pipe | | | | outdoor weather sensor (weather compensator) |
| or into a seperate drainage pipe that leads outside. | | | | for maximum efficiency. |
| A circulating fan then blasts the remaining waste | | | | - If your condensing boiler is oversized for the |
| gas up the flue and away from the property. | | | | task, it will be a lot less efficient that the proper |
| Compared to standard non-condensing boilers | | | | size could have been. |
| which peak at around 75% efficiency, condensing | | | | - Your system will require a Power Flush to be |
| boilers can be anywhere from 83% to 92% | | | | carried out before the new boiler is installed. |
| efficient, giving them a SEDBUK rating of B or A | | | | - A chemical inhibitor such as the industry |
| respectively, the highest possible. | | | | standard Fernox MB-1 will need to be added to |
| What are the Pros of installing a condensing boiler? | | | | the system. |
| - They use less fuel and can be anywhere from | | | | Final Thoughts |
| 15-30% more efficient than non-condensing | | | | Contrary to popular opinion based on information |
| boilers. | | | | over 4 years out of date, condensing boilers are |
| - In real terms, a family with a £400 annual fuel | | | | no less reliable than their non-condensing cousins. |
| bill could expect to cut up to £60 per year off | | | | Early condensing oil boilers had rust problems |
| that total. | | | | caused by the acidic condensate but modern heat |
| - Using a high efficiency or HE condensing boiler | | | | exchangers use non-iron metals to minimize or |
| can lead to significant savings in your heating bill. | | | | completely remove this possibility. |
| - They generate lower CO2 emissions than other | | | | If your existing boiler is more than 15 years old, |
| types of boiler available. | | | | replacing it with a high efficiency condensing boiler |
| - Each year a high efficiency condensing boiler | | | | could save you money, lower your carbon |
| could cut your carbon footprint by up to 1.7 | | | | footprint and contribute towards saving the |
| tonnes. | | | | environment. You may even qualify for the |
| - They are no more difficult to install than | | | | Government's Boiler Scrappage Scheme if you |
| traditional non-condensing gas boilers, and come in | | | | hurry! As long as your home is sufficiently |
| a wider variety of sizes. | | | | insulated, you have the central heating system |
| - Many models will comfortably fit into a kitchen | | | | fully and completely flushed before having your |
| cupboard. | | | | condensing boiler fitted by a Gas Safe Registered |
| - The majority of high efficiency condensing | | | | installer, there is no reason at all why your boiler |
| combi boilers makes no more noise than an air | | | | should give you any problems. |
| conditioning or PC fan. | | | | |