A Gas Safety Check Benfleet engineer will fee the ventilation in both room, take a look at combustion

https://johnnyhazn020.rivetgarden.com/posts/gas-safety-check-benfleet-ensuring-carbon-monoxide-safety

A Gas Safety Check Benfleet engineer will look at various the air flow in every single room, try out combustion, and make sure that flues aren't blocked or incorrectly outfitted.