Do You Have A Remedy For Cold Water Surge In RV Shower?

Updated 06/30/2025 | Published 06/18/2025

Question:

Do you have a remedy for cold water surge in rv shower ? Thank you

asked by: Dale E

Expert Reply:

Hello Dale, thanks for reaching out. I may have a solution for you, but I am not quite sure what you mean by "cold water surge".

Are you having problems with your water heater where the water will go hot, then get cold for a moment, then hot again?

Or are you referring to cold water coming out of the shower when you turn the hot water on, and it takes a while to get hot?

If you can elaborate a bit more on what is going on I am happy to look into it and see what I can do to help.

expert reply by: Jesse M

Dale E.

6/24/2025

When I pause the water output on my shower head unit, then turn the water back on, I get blast of cold water for a couple of seconds then the temperature becomes stable.

Jesse M.

6/25/2025

@DaleE Assuming you have a tankless water heater, that is normal. They all do that and I'm afraid there is no solution for that. If your water heater is tanked, something is wrong.

Dale

6/29/2025

@JesseM. Hi Jesse, I do not have a tankless water heater.

Jesse M.

6/30/2025

@Dale Interesting. If you are leaving the water off for a minute or two, this could happen from water just sitting in the pipes and cooling off. Especially if you are somewhere colder. If you are turning the water off, then immediately back on, it should get hot almost immediately. If it isn't, this means somehow the hot water plumbing is getting combined with cold water. It could be your water heater bypass valve is partially open, or damaged and is letting cold water mix in when it shouldn't. This is probably something you would want to have an RV tech come take a look at, that is unless you are well versed in RV plumbing.