Latent Defect - Plumbing Edition

EmsLdn

Hello all,

Hoping for some advice and guidance. 
Bought a new build from developer Dec 2018. In May 2020, the main bathroom leaked into the kitchen below. The developers sent a plumber who checked under the bath and said it was probably the waste pipe under the bath. They replaced that part. October 2020 a leak was detected again into the kitchen below - developer sent a plumber - this time, they took the frame for the shower door off the bath and sound a large spot where the tiles had not be grouted and sealed. This was repaired and the edge of the bath was also resealed. 
Saturday last week, a leak from the bathroom tripped the electrics in the kitchen again. The property is now almost 3 years old, so I called my insurance company for their out of hours emergency home service. The plumber who came out tried to find the source of the leak. They filmed a video of water coming in through the wall mounted mixer tap (the tap operates water into the bath or via the shower - a combination mixer tap). The plumber said it looks like this has been going on for a while and that I should talk to NHBC or my house builder/developer. NHBC are unwilling to send someone to investigate. The house builder are unwilling to send someone to investigate. 

I'm in the process of trying to find a plumber to come and quote for the work to resolve the leak but I wanted to know if this sounds like a latent defect? This is something the representative from the NHBC mentioned when I spoke to them. The potential headache of seeking legal representation to attempt to force them to resolve something that most likely wasn't resolved in the first place is not something I relish.

Does anyone have experience of this sort of issue? Was it resolved without legal intervention?

I understand that defects detected/reported after 2 years are my responsibility to resolve as home-owner - My feeling is that without investigation, how can the house builder or NHBC say whether or not this issue is a latent defect or not?

Thanks in advance

Doozergirl

NHBC only cover major structural issues and it's arguable whether they  even do that much of the time.  You will get nowhere with them at all. 

The builder is out of their 2 year snagging period.  I'm not sure  I fancy your chances there either, tbh.  Depends on how much of a fight you want.