do all boilers need a flue?

Doglover88

just moved into a place that has a huge combi bolier in the kitchen and i want to replace it with a new smaller unit, possibly re-housing it in a space that is adjacent to an outside wall. Do all boilers need a flue or can you get ones that dont?
cheers
glen

N9eav

All boilers need an air source and an exhaust source. I believe the new generation of boilers are condenser type, they condense the water vapour produced in the exhaust and the water goes into the drainage system. The gases however must go out through a flue, usually this can be a hole in the wall with vent cover. I am sure a real heating engineer will answer this in due course.

Mr_Proctalgia

All new boilers are supposed to be of the condensing type now, this is subject to placement, because of that fact they tend to be physically larger than what we are used to. That being said the older type boilers are still available from places like eBay and some plumbers merchants. Bear in mind that condensers can be as much as 95% + efficient if coupled with the correct size radiators (Its all to do with the Delta and the temperature of the returning water) The flues on most new boilers are fan assisted and can be quite small in diameter, you are allowed to generally run them for up to 3 meters, some allow shorter runs with bends in them too.
IMHO the boiler is one item that really shows the old adage of "You get what you pay for" in its true light. As far as Combis go; go for the hot water flow rate you want, not the central heating ouput, they are all modulating nowadays and turn themselves down to match the heating load.