What to do if a wrong chimney has been installed?

Doesn't the whole thing have to be approved by the chimney sweep anyway? In the worst case, you are not allowed to put the fireplace into operation.

Can't a fresh air duct be installed INSIDE the flue pipe if it is that large? Of course, not a makeshift solution, but an approved system.

Otherwise, surface-mounted solution :cool:

Extracting the air from the living area will not work either, because a well-sealed house does not provide enough air to flow in. Is the stove located on an exterior wall or is there a basement beneath the stove?

Neither. It is in the hallway on the ground floor, on an interior wall. On one side behind it is the kitchen - in front of that is a custom-built kitchen cabinet. On the other side is the living room. When we opened the flap in the living room last night, the stove burned very well. Originally, we had a CD shelf in front of the not-so-nice flaps, which we would move once a year – when the chimney sweep comes. The shelf is now gone. My husband says it can’t be changed anymore. Leave the flap open, place a plant loosely in front of it. When the stove is burning, open all the doors in the house, then there is enough oxygen available for 120 sqm; if necessary, occasionally open a window. I read somewhere that 5 sqm of living space is required as air supply per kW of stove power. The stove has 4.9 kW.

Doesn't the whole thing have to be approved by the chimney sweep anyway? In the worst case, you are not allowed to put the fireplace into operation.

The chimney sweep has already approved everything. He was full of praise. Everything is great. Good stove. Good company.

Can't a fresh air pipe be installed INSIDE the flue pipe if it's that big? Of course not a makeshift job, but an approved system.

Otherwise, surface-mounted solution :cool:

Where should the surface-mounted solution go? It would have to go through the ceiling by core drilling, through the upper apartment, through the attic, all the way to the roof?

The chimney sweep has already approved all of this. He was full of praise. Everything great. Good stove. Good company.

If the chimney sweep gave his approval with praise, you shouldn't need to open the flap or place a plant in front of it.
If the stove doesn't get enough air, the chimney can't draw properly either.
So much can go wrong here. Several people have already died because they underestimated the dangers.
Remember, we are talking about fire inside the house.