To get email notification when someone adds to a thread you're following, click on the star in the thread's header and it will turn yellow; click again to turn it off. To edit your profile, click on the gear.
The Wall has a powerful search engine that will go all the way back to 2002. Use "quotation marks" around multiple-word searches. RIGHT-CLICK on the results and choose Open Link In New Window so you'll be able to get back to your results. Happy searching!
In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Need to contact us? Visit

Expansion Tank

[Deleted User][Deleted User] Member Posts: 9
Plumber I'm thinking to hire says I don't need Expansion Tank for my DHW.

I'm planning to have Lochinvar Knight boiler with Lochinvar 80GAL indirect water heater. There is NO recirculation line for hot water.

Plumber states since there is no recirculation line, no expansion tank needed.

Is that true? Please help me understand.


  • SWEISWEI Member Posts: 7,090
    Some codes

    require them for all installations.  From an engineering standpoint, anytime you have a check valve (or something that acts like one) between the incoming water supply and the water heater, you need one.  PRVs act like check valves.
  • R ManninoR Mannino Member Posts: 420
    North Shore or South Shore?

    The north shore has higher water pressure which has presented a problem sometimes. I recommend the DHW expansion tank and some manufacturers require it for the warranty to be in effect. Just my two cents.
This discussion has been closed.


It looks like you're new here. If you want to get involved, click one of these buttons!