A Gas Safety Check Benfleet engineer will check the ventilation in each and every room, attempt combustion

https://lanedsal722.zenbloomer.com/posts/gas-safety-inspection-benfleet-keeping-appliances-turned-off-safely

A Gas Safety Check Benfleet engineer will inspect the air flow in every one room, examine combustion, and look at various that flues will not be blocked or incorrectly fitted.