Ferroli Modenas installed 2014 to 2015. installed 6 of these, 4 of them leak the same place, under the pump. Ferroli refuse to fix, even though they are still in warranty. Their customer service is the worst I have ever known. They tried to deny they were registered. If I fix warranty is null and void. I have heard the leak is pin holes in the pipe with in a pipe heat exchanger. help Please!