One way valve on hot water in shower

[arcsum68]

Hi, I am not able to find what I am looking for and was hoping someone could point me to some literature or instructions on adding a one way valve to the hot water side of the shower valve. I watched a video awhile back where they mentioned they did this, but offered no details. Per the video when you use the switch on the showerhead to shut off flow, the cold water will back fill into the hot water side since the pressure is greater and thats why when you turn it back on it will be cold for a few seconds. By adding a one way valve to hot water side that cold water cannot get into the hot water side. Any recommendations on how to accomplish this?

[Old-Biscuit]

Need access to HOT water line to shower faucet
Then install a check valve in Hot line

**Doesn't have to be right at the shower faucet ...just needs to be on Hot line going to shower faucet

[opnspaces]

Buy a Sharkbite check valve. Link

Cut the red PEX tube coming out of the water heater and add push the valve onto the line being careful to observe the water flow arrow.


Are you having a problem with the cold water blast in the shower or does the one way valve just seem like a good idea.

Many RV water heaters already have a check valve at the exit line, it's possible yours already has this.

Does your RV shower head should continue to dribble water out of it even when you flip the switch off. This is to prevent the cold water blast as the pressure can't build up enough to backflow the line.

If your shower head shuts completely off, you can avoid the cold blast by only shutting it mostly off. Leave a little dribble out of the head and the cold blast won't occur.