Vertical Flu left in place ??

[Richard83]

Hi all, my plumber has installed a new boiler in place of the old one. The old one had a vertical flu that terminated out the top of the roof this new one is horizontal. The plumber has left the vertical flu in place, I asked him why it’s not being removed and he told me it doesn’t matter because it will never leak. It doesn’t seem rite to me. Any reasons why this shouldn’t be the case ?

 

[ShaunCorbs]

Yep shouldn’t be left in lazy and draughty

 

[fowlerboi]

It will 100% leak. A bit of driving rain will force water down the flue and into the house

 

[jonesghd]

Leaving the old vertical flue in place when installing a new boiler with a horizontal flue is not recommended. It can lead to ventilation issues, non-compliance with regulations, and potential leaks. Consult a professional or the boiler manufacturer for proper installation guidance and removal of the old flue.