In co-ownerships, most water heaters (electric or gas) are installed within the apartments. In such a case, this device is an integral part of the private portions of the building. Each co-owners therefore has the responsibility to ensure the proper functioning, by checking (notably) any signs of dilapidation, and, if necessary, by replacing it at its own expense. Failing to do so, in the event of a breach, a co-owner could be held liable for any damages to the common areas of the building, as well as to the private portions owned by other co-owners, up to the amount of the deductible provided for the syndicate's insurance coverage.
Just like any other natural or legal person, a syndicate of co-ownership may be held civilly liable towards third parties, including co-owners.