If you have selected home emergency cover on your policy then you may be covered for the repair of the leak.
Some policies offer cover for tracing and accessing the leak and will pay reasonable costs. For this to come into force there has to be damage to your buildings caused by the water, otherwise the cover will not apply. In this instance you could contact a local plumber to find and repair the leak. Ask them to show the cost of the repair on the invoice and the cost of tracing and accessing the leak separately.
Under Buildings cover is usually provided for loss of, or damage to the building caused by an escape of water. Likewise under Contents cover, your contents would be insured against the same cause of damage.
You need to ensure that your property has not been left unoccupied for longer than the term specified on your policy. If you are going to leave the property for more than the specified time you need to contact your insurer to check they will still provide cover. If they still offer cover they may add endorsements to your policy. Please ensure you read and understand these.