Limited hot water at other fixtures in house after installing new shower valve(no cartridge yet).

Could cold water be bleeding back into other fixtures in house because cartridge is not installed yet? I called delta and they said no, but water is hot at gas water heater but doesn't get hot at guest bath.

 

From what I read, yes. Search for the following in a search engine:

"Used to plug one inlet side (Hot or Cold) to prevent cross flow when checking for leaks before the cartridge is installed"

The RP46079 test plug is discussed in https://terrylove.com/forums/index.php?threads/delta-r10000-rough-in-valve-questions-and-more.46986/

 

THANKS!

 

That subject is discussed in their installation manual...they used to include that plug, I think they no longer do, and it is an optional part. The easier thing to do is to just install the cartridge if you don't have the plug, or, if the shower valve has integral stops, shut them off.

 

Unfortunately, a manual didn't come with my valve body when I got it from supply house. I just got back from picking up plug. It's installed on cold water inlet and there's plenty of hot water!

Thanks for your input!