Noisey Hot Water Flow

Everyone, Thank you all for your hlp. The two check valves I just installed are brass and have a 3/8 to 1/2 inch orafice. I also checked the water lines and they are secure. I am going to first try removing the cold water inlet check valve and replacing it with a simple brass coupling to see if it works. The hot water exit check valve is needed for the winterizing by-pass system to work. Again, thank you all for your help.

dougrainer wrote:

Old-Biscuit wrote:

dougrainer wrote:
IF you have a check valve at both the intake and exhaust for the water, that is the problem. Depending on how your system is installed will determine which check valve to remove. Usually, the intake(bottom check valve) is there because of the type winterizing system the OEM installed. There is no real reason to have the top check valve installed. If you remove the top, the noise will probably go away. What your problem is, with 2 check valves that is a restriction on both ends and causing that noise. Some Plumbing codes(not RVIA codes) dictate that there be a check valve on both the In and OUT of the water heater. Years ago, this was a problem on RV's built in California, as California had a state plumbing code that dictated both check valves and RV's had that noise problem. Once California modified the plumbing code to only require 1 check valve, that noise went away. Since the RV's we sold were not in California, we removed the Out Check valve to remove the noise. Doug

Except OP has a Winnebago
Only 1 valve.......Cold water inlet/bypass
Need Check valve in Hot out to stop backflow into WH Tank when bypassed
Don't need check valve in Cold inlet as 3 way diverter valve stops flow into WH tank when bypassed

The OP clearly stated he replace the 2 check valves. That means he has 2 NOT one. Doug

YES OP has 2 check valves

YOU told him to get rid of one in HOT out


BUT OP only has ONE SHUT OFF (3 way diverter valve)
That 3-way directs water to cold inlet OR to bypass

So NEEDS the check valve in HOT out


Comprehension vs just responding goes long way.

Old-Biscuit wrote:

dougrainer wrote:
IF you have a check valve at both the intake and exhaust for the water, that is the problem. Depending on how your system is installed will determine which check valve to remove. Usually, the intake(bottom check valve) is there because of the type winterizing system the OEM installed. There is no real reason to have the top check valve installed. If you remove the top, the noise will probably go away. What your problem is, with 2 check valves that is a restriction on both ends and causing that noise. Some Plumbing codes(not RVIA codes) dictate that there be a check valve on both the In and OUT of the water heater. Years ago, this was a problem on RV's built in California, as California had a state plumbing code that dictated both check valves and RV's had that noise problem. Once California modified the plumbing code to only require 1 check valve, that noise went away. Since the RV's we sold were not in California, we removed the Out Check valve to remove the noise. Doug

Except OP has a Winnebago
Only 1 valve.......Cold water inlet/bypass
Need Check valve in Hot out to stop backflow into WH Tank when bypassed
Don't need check valve in Cold inlet as 3 way diverter valve stops flow into WH tank when bypassed

The OP clearly stated he replace the 2 check valves. That means he has 2 NOT one. Doug

PS, you can also buy the large BRASS check valves that have the correct threads. They have a larger orifice than the plastic check valves and they will probably not have the noise. They also allow more water volume flow.

dougrainer wrote:
IF you have a check valve at both the intake and exhaust for the water, that is the problem. Depending on how your system is installed will determine which check valve to remove. Usually, the intake(bottom check valve) is there because of the type winterizing system the OEM installed. There is no real reason to have the top check valve installed. If you remove the top, the noise will probably go away. What your problem is, with 2 check valves that is a restriction on both ends and causing that noise. Some Plumbing codes(not RVIA codes) dictate that there be a check valve on both the In and OUT of the water heater. Years ago, this was a problem on RV's built in California, as California had a state plumbing code that dictated both check valves and RV's had that noise problem. Once California modified the plumbing code to only require 1 check valve, that noise went away. Since the RV's we sold were not in California, we removed the Out Check valve to remove the noise. Doug

Except OP has a Winnebago
Only 1 valve.......Cold water inlet/bypass
Need Check valve in Hot out to stop backflow into WH Tank when bypassed
Don't need check valve in Cold inlet as 3 way diverter valve stops flow into WH tank when bypassed

Check valve or large piece of sediment in an inlet or outlet somewhere. Mine's being doing it for years.

IF you have a check valve at both the intake and exhaust for the water, that is the problem. Depending on how your system is installed will determine which check valve to remove. Usually, the intake(bottom check valve) is there because of the type winterizing system the OEM installed. There is no real reason to have the top check valve installed. If you remove the top, the noise will probably go away. What your problem is, with 2 check valves that is a restriction on both ends and causing that noise. Some Plumbing codes(not RVIA codes) dictate that there be a check valve on both the In and OUT of the water heater. Years ago, this was a problem on RV's built in California, as California had a state plumbing code that dictated both check valves and RV's had that noise problem. Once California modified the plumbing code to only require 1 check valve, that noise went away. Since the RV's we sold were not in California, we removed the Out Check valve to remove the noise. Doug

Just thinking....since you have already checked/changed the check valves, I'd try draining and flushing the tank. Lots of gunk and sediment can build up inside.

RV hot water tank rinser:

I wonder if there is a water line that is vibrating because it is not fastened tight somewhere alone the route to the tap.