Groaning noise from HW tank

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rankjo

Well-known member
Joined
Mar 3, 2005
Posts
337
Hi, I searched the site but didn't find the answer. This must be a common thing though.
When the HW is turned on, there is a groaning noise from the back of the HW tank at the outlet. I can't see back there but I can get my hand on it and there is a vibration at the right-angle in the plastic pipe just as it leaves the tank. There is no vibration in the brass outlet. It is worse with more flow. The HW pressure seems the same as usual, but it is very slightly less then the CW flow, which is what I would expect.

I'm suspecting those white deposits I flush out of the tank every lay-up time are partially plugging the outlet.
Would that be right?
And where would I find a competent dwarf to crawl in there, take it apart and clean it?

Thanks  Rankjo
 
Sounds like one of the check valves. Fairly common problem. Some people remove them, some remove the guts from them. I preferred to replace mine.

However I had to get one of my nephews to do it as there was no way I could get by big butt in there.

If you remove it, there will be a plastic pin and spring inside, maybe you could clean it.
 
Yah, sounds like the check valve, various things can cause it to vibrate, including a weak spring inside from normal use over time. Personally, I'd remove it and replace it with a 1/2" NPT galvanized or plastic/nylon pipe nipple, then re-attach line fitting. Double check washer is in fitting still and not stuck in old check valve when re-assembling. A new brass check valve isn't that expensive if you prefer to replace it with new.
 
Agree.... Most likely the check valves.. You may have two.. (one on the cold water inlet to the HWH and one on the hot water outlet of HWH).  I replaced mine with brass check valves about 9 months ago.  My problem is back.  I wish I had just gotten rid of the check valves completely.  That is my next project.  I may just gut the inside of the check valves and re-use them. 
 

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