There are all sorts to consider when when choosing a new boiler theres the obvious - cost, size and make. But what you also should be looking at is the running cost, how efficient it is, how many radiators you can run off it and how much hot water it will produce. All boilers do the same job as they all heat water, the only thing that separates them is how they do it. Whether on a sealed or open system the boilers are categorised into three location types:
Wall mounted - fixed up on the wall.
Free standinding - fixed to the floor.
Back boiler unit (b.b.u) - located in the chimney breast behind the fire.
Next we will give you something to think about when deciding to get a new system or just repairing what you have. Giving you the advantages and disadvantages of the different types of systems.
Things to consider:
Combi boilers take up less room in the home as you don't need a cylinder.
People with cylinders often use the cupboard its in as an "airing cupboard" to dry their clothes in.
Check the hot water flow rate when purchasing a combi its given in litres/minute or galons/minute sometimes. This is how much hot water you can get in a set time.
Boiler output - this is an indicator of how the boiler will perform in producing heating and hot water. This is measured in kw or btu/hour.
The law now states that any new boiler you install now must be a condensing boiler unless you meet the very exceptional circumstances (a point system where you have to earn so many points to qualify).
Condensing boilers produce a plume from the flue when in condensing mode - think of the steam coming out of your kettle when its boiling. They also require a condensation pipe running to a drain/gully or soak away.
By slowing the flow of hot water from the tap (not opening it fully) you allow more heat to be passed from the boiler to the water, giving you hotter water. On the downside activities like running a bath can take alot longer (most modern combi boilers actually give a decent amount of flow rate now).
When you run off the hot water store on a cylinder you have to wait while the fresh water is reheated to temp. So the first person to get a bath is fine but the next may have to wait a while.
Old boilers aren't as efficient as their new counterparts so you have to burn more gas (the price of which is going up and up) to heat your home. A lot of old boilers have permanent pilot, which may not seem much but think of the cost of keeping that pilot going of a year.
Older type boiler where made of thicker cast metals and have generally a lot less components. Less components equals less things to go wrong equals less costs.
When choosing the brand of boiler stick to a name you know and trust. That manufacturer that no-one has heard of maybe slightly cheaper to purchase, but how reliable is it? When it breaks down will your tradesman be able to get parts or even be trainned to work on that boiler?
From 1 April 2005, Part L1 of the Building Regulations requires gas and oil boilers installed in new and existing premises to be condensing types, with a SEDBUK efficiency in band A or B, unless there are exceptional circumstances that make this impractical and/or too costly. In those cases where it is considered difficult to install a condensing boiler, an assessment procedure is used to demonstrate that a non-condensing boiler is justified.