what are the advantages and disadvantages between a combi boiler and a conventional boiler?

Answer 1

Combi boiler advantages

1/ quicker and cheaper to install
2/ around £150 per year cheaper to run.
3/ Showers are at mains pressure around 3 bar or more so no need to install expensive and noisy shower pumps.

Disadvantages

1 / No back up system (immersion heater) if the boiler breaks
down
2 / more to go wrong on a combi boiler than an old type of conventional boiler but just the same if its a new type of conventional condensing boiler.

Answer 2

Combination boilers are of two types; instantaneous where water is heated as it is required, and a storage where the boiler has a store for hot water. Both types negate the need for a hot water cylinder and save some energy lost through keeping this store of water hot. (link 1 below)

Generally speaking in the UK, all gas boilers installed or replaced since 1st April 2005, or oil fired boilers installed or replaced from 1st April 2007, must be of the condensing type if it is practical to do so (link 2 below), and the boiler forms part of your central heating system.

Condensing boilers are more efficient as they extract more heat from the flue gasses (typically 88% versus 78% for a conventional boiler). One downside is that when operating you are likely to see a plume of steam coming from the exhaust on the outside of your home. The third link below gives more detail on condensing boilers.

Answer 3

combi's will give you hot water when you want it and not store any in an immersion tank. this is a prob i have had 3 in dufferent houses, you have to run a lot of water each time you want hot water as it takes a long time to come through. and if you have the hot tap not on full, the water demand will not be enough to ensure it stays hot, theyre a real pain like that but for efficency they only heat what you use but you waste a lot of water getting the heat to the tap.
ordinary boilers store hot water and once you have used whats in the tank you have to wait for it to heat more. energy wasting in that they use energy to store hot water but if you have one keep it till it fails its not worth changing just for the sake of it.
combi's are more efficient. dont get it fitted by gas board they charge excessive amounts. but they do a maintenance scheme for about £13 a month which is ok.

Answer 4

The only problem with a combination boiler is the fact that you cannot put an electrical shower pump to boost the water pressure, because you cannot use an electrical shower pump on mains pressure. As long as your mains pressure is fine, then a combination boiler is fine. It is also less plumbing work and problems.

Answer 5

combi::>no hot water cylinder,no tank in the loft,instant hot water!
conve::> water cylinder(airing cuboard?) tank in the loft(stored water if required) "had both go for conventional "hot water can be instant if programer is controlled right