Hi, I've recently had an air admittance valve fitted behind my shower, they had to cut a hole in my bathroom wall to access the soil stack, I've noticed it says this should be accessible in case of problems/servicing but once they have repaired the hole in the wall it won't be.
Want to check it is ok before they close it all back up, presuming its not safe not to have one fitted as it caused damp from the condensation & mould & smells which was why they cut the hole in the first place!!???
Any advice great!!