Shower check valve?

[Remodeler]

Here's a silly question. I was going over things in my head (not good). Does a custom shower need a check valve on the hot water line to prevent cold water from going back to the hot water heater. Or does the shower trim and cartridge prevent the cold water from doing this. I might be over thinking all this.

Basically, I installed my rough valves and shower heads today along with all my new piping (thanks to all y'all forum help). I plugged up the shower head for a test run and everything looked good. I decided to leave pressure on the system for a while to check for leaks. In the meantime, I got distracted with another home project and the boss lady went to take a shower. She ended up with a cold shower! I assumed all the cold water had a bit higher pressure and made its way thought the rough valve (no cartridge)into the hot side giving her a not so pleasant shower.

I assume that when I install the rest of the shower guts this will not happen in the future. But, I just want to make sure y'all agree. Thanks for your input.

 

[johnjh2o]

Sounds like you installed a Delta faucet. Good choice. Your problems will end when you install the cartridge. No check valve needed.

John

 

[Remodeler]

Ah yes. A delta. You know your stuff. Do not all other products work the same way?

. Does that mean the Delta product is a good thing?

 

[johnjh2o]

What Delta is doing is using one valve body that can be used with many different styles and finishes. Which is a great idea. In supply houses the valve body is sold separably from the cartridge and trim. They ship a cap with the valve body so it can be tested. But without the cartridge in place it allows the hot to mix with the cold. What were starting to see is they also shipping a small plastic cap with a O ring on it that installs into the hot or cold seat in the valve body before the test cap is installed. This solves the problem you are having. Without having to install the cartridge.

John

 

[Remodeler]

Thanks for your help john