Condensing Boiler Flue

[phil284]

In a condensing boiler, how exactly does the water that comes back down the flue get drained away and not get into the boiler?

I know there is some sort of pipe + it might be different for different boilers, but how does it get drained away?

 

[kevplumb]

it does get into the boiler

drains down to the bottom and collects in a sump

that is where the drain is attached

 

[phil284]

thanks. Got a conventional boiler where water is doing that at the moment ... and causing it to go rusty on the heat exchanger & fan.

Just want to make sure the condensing one is going to be ok with that ... but guess it is as it is made to do it!

Will the inner flue be plastic generally?

 

[kevplumb]

generally yes

 

[phil284]

one more quick question:

is the boiler designed so that condensate can potentially come back down the flue?

 

[kevplumb]

its designed so that it does

 

[phil284]

some websites say it is primarily to collect liquid from the second heat exchanger, so just wanted to make sure

sorry for the novice questions....

 

[kevplumb]

no probs

the idea of the condensate running back to the boiler is to stop the flue terminal dripping outside