Actually, the loss assessor works on the Insured's behalf.
A loss adjuster works on behalf of the insurance company.
It sounds to me like they will only pay what is called "trace and access" - which basically means, the cost of tracing and accessing the leak. This is usually applied in circumstances where your water leak was due to "normal wear and tear". Policy conditions unfortunately. No way around it. I presume you have reported it to your insurance company. If so, a loss adjuster should have been sent out immediately on behalf of your insurance company.