Please send more info. Where is the expansion tank located, on the cold water service or the hot supply? What is condensating in the attic? Pipe? Bill The Local Plumber Tustin, California http://www.TheLocalPlumber.com
Thank you Bill.The expansion tank is on the hot water supply .The tank is hot say about 75 degrees centigrade Condensation is forming on the attic roof inner side. The tank is open on top.