Bathroom tile and other issues

Hi, Hope someone can advise me on the following issues. I'd really appreciate it.
So our house is 7 years old. It has a 10 year warranty.
When we built we asked for floor waste holes in case the bath ever overflowed. They did this at extra cost, but when it was built they never connected it properly so water does not flow through. So we have to flush it with water every month to avoid smells. The builder told me 'its fine, just flush it'.... (at least I feel they should have refunded my money)!

Issue 2. So we had some grouting that kept popping out. It had been fixed about 2 or 3 times by builder and then when I cracked it, they called in a guy from Grout Pro who charged them quite a bit. So he repaired it about 18 months ago from memory. So a couple of weeks ago when cleaning the floor, i got annoyed by the 'cancer' on the grout lines. I googled and it said it was as a result of moisture under the tiiles. I thought'how can that be. Upon closer inspection I see that the grouting has come away from the edges of 2 tiles. When I stood on the tile it made a whoosing noise and quite a bit of water oozed out. The water was very smelly making me wonder how old this trapped water was. They are coming to look at it today>

My questions are: Should they remove the tiles - and how many, to inspect the waterproofing and allow things to dry out. Because I have a feeling they will just want the area to dry out and then re-grout.

Any advice welcom. Thank you in advance

Hi traceyem they should definitely remove tiles and let it dry out. The amount will only be determined on site by whoever is doing the rectification. Yes they probably will want to just regrout but this is only a band aid solution and the incorrect way. They won't be able to see the waterproofing as there is a sand and cement bed under the tiles. This bed will have to be dryed out and the tiles redone and regrouted. Good luck

Thanks Abasnsw...EEEEK...I hope I dont have a big fight on my hands!