[Sarm]

If I have an application where a large Hot water GPM is needed such as a healthclub with multiple showers, Would it be better to pipe then in parrellel or in series? They are piped in parralell now but are having issues with inconsistant hot water temps?

 

[TheEplumber]

You want to put tankless heaters in series?

 

[TheEplumber]

Do you have a storage tank?
http://www.rheem.com/pdfs/_temp/11000series/11120.pdf

 

[Alan]

Don't forget that when someone uses the tankless heater, they will get a hot shower. Once they turn it off, the line is full of hot water. When the next person turns on the water, they will get full hot, but there is also a delay (time varies most common I hear of is 3 seconds) where the heater has to sense a flow of water to turn on. That means you get hot hot hot.... cold cold cold... and then hot ---------------


Perhaps this is the issue that you are having?

Having them plumbed in parallel would not give you inconsistent temps unless there is something wrong with the unit.