Rented old house, 3 out of 5 room windows are stuck shut. Does the landlord have an obligation to fix them to ensure they open?

Pretty much as the title says, I've just moved into a 1880s house with single glazed sash windows. The whole place is in a fairly sorry state but manageable. My main concern is the windows not opening, one for the lack of fresh air, but also as potential fire escapes. It's a narrow 3 floor building and both bedrooms on the first floor are swollen/do not open. The ground floor living room window is the same. These are the only windows in the rooms.

Is there any legal obligation for the landlord to sort them or is it pointless trying to argue a case?