expansion tank install Home › Forums › Public Forums › General Plumbing › expansion tank install This topic has 2 replies, 3 voices, and was last updated 20 years, 9 months ago by Harold Kestenholz. Viewing 2 reply threads Author Posts 5 Aug 2003 at 12:40 am #276822 MasterPlumbersKeymaster I have a teledyne minitherm 2 gas boiler. should the expansion tank be installed horizontal, vertical – or does it matter??? 5 Aug 2003 at 10:55 am #294839 Retired plbg1Participant Most of the ones I saw installed were hor. unless specified different. Ask where you got the boiler if it makes any difference, seems like Hor. you have more expansion room. 5 Aug 2003 at 7:00 pm #294840 Harold KestenholzParticipant The expansion tanks used with newer boilers for the past 20 years are installed hanging from the nipple that connects it to the system at the top, as in here: http://64.226.150.132/hydronic/des/start.htm#Expansion The older expansion tanks without a diaphragm were installed horizontally. Author Posts Viewing 2 reply threads You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In