The list of exclusions in any household insurance contract can be significant.
For water damage to a carpet the following would be taken into account.
1. If the damage was due to your fault (e.g. bad diy plumbing) and you did not have accidental damage cover.
2. If the carpet was old and you did not have "full replacement" cover or "new for old".
3. If there were specific exclusions e.g. leaks in a holiday home where the policy required the water to be turned off during the winter.
4. If your cover was not high enough.
5. There are several areas in the country where flood damage is not available or carries a very high exclusion (i.e. first 10,000 euro of damage may not be covered).
This list can be large and the attitude of the insurance company as well as your previous claims history would also be a factor.
As a starting point look at your policy document (sent out annually) and if necessary request a copy of the policy handbook (which contains the full terms and conditions).
The main thing is to get the claim in early. Unreasonable delays can impact your claim.
Finally an option - in large claims - is to engage your own Claims Assessor.