Gas boiler expansion tank question?
I have an older 1950's model American Standard gas boiler. Going to the expansion tank is a thin gauge copper pipe divided into 3 sections with valves between each section. When the boiler is running the entire copper pipe leading to the expansion tank gets very hot. After the boiler stops about 10 minutes later the 2 sections of copper pipe closest to the expansion tank get cool. The section of copper pipe furthest away from the expansion tank which runs directly into the boiler pipes stays very hot. Is this normal? Also, if I drop the temperature in the house from 68 to 63 will the pressure needed to run the boiler drop? At 68 degree the cold pressure is around 14, hot around 17-18. Thank you!