Hot water pipes whine

Old-Biscuit wrote:

rv2go wrote:
It may be possible that you have 2 check valves.
When I heard that whine when using hot water, I replaced the check valve at the water heater.
Still had the whine.
Called Winnebago and was told there was a 2nd check valve and was told where it was located. Of course it was an arms length to reach. I got it out and removed the broke plunger and reinstalled it.
No more whine..

Could be a check valve on cold inlet fitting at WH Tank

But thought that was a 'Winnebago' thing ---for some reason they think it is necessary
It ain't :B

I believe it is necessary if you want to use the HW heater bypass (as one convenient valve) to winterize. If you install a valve in place of the check valve, then you don't need the check valve.

It's definitely not a Winnebago thing - every 5er we ever owned had the same check valve and they all hummed eventually and had to be replaced.