Thumping Sound When Flushing Toilet

[Bohowanderlust]

Last night we started hearing a thumping/hammering/vibrating sound whenever we flush the toilet, sound can not be reproduced when using faucets.

I've searched here on the forum but didn't find any suggestions. I Googled it and found similar complaints regarding the "Water Pump", but we are not using the water pump. We are hooked up to "City Water" at a State Park, where we've been before but not at this same site. We've called our dealer's service dept since they replaced our whole toilet about a month ago, but as always they seem useless in helping us, saying they've never heard of such complaint and they are overbooked to get us in anytime soon.

What we've tried so far, though we tried all of this the noise is still happening:

~ Read about "Hammering" pipes and water flow. It was recommended using a Water Pressure Regulator. We already have one in place.

~ Also was recommended to use two Water Pressure Regulator, one on spigot end and one on rig.

~ Dealer suggested taking the Water Pressure Regulator completely off.

~ Dealer suggested turning the spigot water flow down...tried 1/2 way on then tried only a 1/4 way on.

~ Opened side compartment to look at the pipes behind City Water inlet...nothing is vibrating there. Sound seems to be coming from deep within the belling of the beast. LOL

Help! Any suggestions? We are concerned about pipes busting etc.

Thanks in advance!

[fatcatzzz]

This does sound like water hammering. As a good regulator should help, I have had good luck in our SB home with these.
http://www.watts.com/pages/_products...s.asp?pid=7880
They are easy to install.
Hope this helps.

[mtlakejim]

This might be a long shot but does the hammering sound like the black water tank straps are loose and the tank is bouncing against the floor? Does the sound happen when you put water in the bowl or when you dump it to the tank?

[Bohowanderlust]

Thanks FATCATZZZ we found that Home Depot carries the Water Hammer Arrester here locally. We'll be giving it a try.

MTLAKEJIM I don't think it's the black tank bouncing, at least it doesn't seem to, the sound does happen when it empties into the tank, not when filling the bowl, and for a short while afterwards when it fills. But not if you fill the tank first, the sound doesn't happen until you flush.

[Razrbk]

Does it do it when you use your freshwater and water pump?

[Bohowanderlust]

Razrbk purchased it new in April...have not had the need to run the water pump so we don't know if it does it when pump is running. Though in my search I've noticed quite a few complaints that while using the water pump the hammering occurs.

[cpaulsen]

Get a water hammer arrester........mine had that problem and used a water hammer arrester........with the sharkbite fittings. Cut the pex tubing and a section out big enough for the arrester and slid it.....no more water hammer.

[Razrbk]

Originally Posted by Bohowanderlust

Razrbk purchased it new in April...have not had the need to run the water pump so we don't know if it does it when pump is running. Though in my search I've noticed quite a few complaints that while using the water pump the hammering occurs.

Thought you might have checked that out as part your problem-solving process - to confirm that it's a city hookup issue & not a problem with your replaced toilet.

[rohrmann]

I am wondering if the hammering is actually coming from the flush valve on the toilet, seeing as that is the only thing that causes the hammering. We replaced our Thetford toilet a few years ago with a Dometic 310, which has worked great. The only glitch we had was several months ago, when it stopped flushing, and I discovered the flush valve had backed out of the housing that holds it in place. After closer checking, I discovered that the replacement valve comes with a couple self threading screws to hold it in place, along with the plastic clips. I installed a couple of screws, and all is good. All this to say, we had the hammering just prior to the valve coming loose from it's clips, so maybe your valve is the problem.