I’ve written about seven replies to this now and you know, I just don’t understand the question.
It’s a pretty simple question!
In my experience – it depends. Some manufacturers can be pretty good at covering costs of reinstalling something, some aren’t. I used to work in the building/Diy trade and the first step in ensuring you get a good result is FOLLOW THE INSTRUCTIONS. We used to get all sorts of claims for labour for refitting stuff and a lot of the time they were rejected as people didn’t do that or didn’t do the “normal” things you are supposed to do when installing stuff. These “normal” things might not be in the instructions but would be the sort of actions which a professional would normally do when working. As a lot of stuff was DIY fitted a lot of people were novices and did cut corners or just simply not do things properly.
So for example a lot of people didn’t know you were supposed to choose tiles with the same batch number but still, after that, mix up the boxes as you go. So many people use to buy 10 boxes and have 3 or 4 different batch numbers on them.
Most of the paint companies were ok with helping customers out but we had to send a sample off to them which they would check against their database, if it varied by more than a normal amount they would normally pay for a repaint – but if you painted it yourself DIY you wouldn’t be paid out for a pro to come and do the job 2nd time!
Triton showers were pretty good – if a unit was faulty they would come out and repair/replace for free during the guarantee period but they always warned that if it wasn’t the fault of the unit (ie something wrong with electrics or plumbing) they would charge quite a bit for attending to check so it was up to the customer to ensure it was the Triton unit at fault.
I would normally expect a manufacturer to help out if there is no way that a fault could be discovered or avoided before the item was fitted. As always, it really depends on the manufacturer as it’s easy to wriggle out of claims and make it really hard for a customer to get what they want even if you should legally do it.
IME consumer law is great, it really is, and it does protect you, but in these cases it really depends on how you or the pro you used acted before and during the fitment (and how much you can prove that) to what result you get in the end.