Water 'Hammering' issue

Just get a water hammer arrester and put in the line the main water line. Had the same problem on my 5ver and that stopped the problem. Bought one off of Amazon that had shark bite fittings on both ends.....and cut the pex line in my storage compartment. Took about 5 minutes to install.

Don't know why one outlet would do it and not others, but a small bladder tank will stop it, or a hammer arrester ???

Search google for water hammer arrester... then select images... lots of photos on what a water hammer idea looks like...

I bet one of those small size 2-Gallon Expansion Pressure Tank LOWES would work too...

Roy Ken

I got the same deal on my commode. I think it is/may be a function of the valve in the commode.

Check for a broken clamp in the area of the noise allowing the pipe to float free. If it just started with no change in water pressure, I would suspect this.

Thanks all!

I've ordered a water hammer arrestor from Amazon (cheap!) with same day delivery....so it will be installed no later than late tonight....I'll report back on the results! (I'll also check for a lose clamp!)

Ok, IN an RV there are TWO causes of "Hammering" not one like in a sticks and bricks

The first (Never heard it in my RV) is caused by the physics of what happens when you CLOSE a valve. this is called Water Hammer and the advice of the others on this issue is dead on.. The "Arrester" is nothing more than an air chamber that absorbs the Hammer.

The other source which is unique to RV's is the on-board fresh water pump.
This will HAMMER when water is flowing.. The Toilet (And Shower) are the major flow items in the RV.. So if the city water inlet is partially clogged or if the city water pressure is low or if there is any "issue" with city water that limits flow such as a aging pressure regulator.. The on board pump, if powered on (Switch is on) may engage and it can Hammer. even with flex lines to/from it it can hammer... It is, after all, a jack hammer.

In the meantime try pinching down on the valve on the post to cut down the flow. May not make a difference but there is no cost to try it.

Get a water regulator the toilet is not designed for the water pressure going to it the valve will eventually fail

wa8yxm wrote:
Ok, IN an RV there are TWO causes of "Hammering" not one like in a sticks and bricks

The first (Never heard it in my RV) is caused by the physics of what happens when you CLOSE a valve. this is called Water Hammer and the advice of the others on this issue is dead on.. The "Arrester" is nothing more than an air chamber that absorbs the Hammer.

The other source which is unique to RV's is the on-board fresh water pump.
This will HAMMER when water is flowing.. The Toilet (And Shower) are the major flow items in the RV.. So if the city water inlet is partially clogged or if the city water pressure is low or if there is any "issue" with city water that limits flow such as a aging pressure regulator.. The on board pump, if powered on (Switch is on) may engage and it can Hammer. even with flex lines to/from it it can hammer... It is, after all, a jack hammer.

A buddy mentioned the same thing about the water pump....we have not used the TT water pump at all...been on 'city' water since we hooked up months ago...I will bleed the outside shower, just in case there is an air bubble.....but why is this problem only happening when filling the bowl after flushing? That's what's puzzling me....!