Home>Discussions>PLUMBING>Loud dripping sound when water is off/no evidence of water damage-ongoing issue
8 posts / 0 new
Last post
alan71
Loud dripping sound when water is off/no evidence of water damage-ongoing issue
alan71

Hello all, We have a loud dripping sound that comes and goes in our downstairs half bath. There's no obvious water damage to any ceilings or carpets. We first heard this noise years ago. I decided to turn the water off to see if that stops the sound and it still is present. It seems to stop for about a minute or two then run out tap tap tap tap tap, then stop again. The ceiling has an attic fan and this is where it sounds to be striking. It sounds like water dripping on metal but we have not noticed any evidence of a leak. Above this down stairs bath there is a bathtub, sink and commode. Any ideas on what this could be? Thanks

A. Spruce
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
A. Spruce

Turn the water off to the upstairs toilet, flush the toilet, then listen for the drip, if no more drips, then you've got a leaking flapper, inlet valve, or the water in the tank is set too high and running out the overflow tube. All of these things will add water to the bowl, water has surface tension, so it will fill until the surface tension can't hold the excess water anymore and it will flow out until surface tension is strong enough to retain the water again, hence the periodic "run, drip, drip, drip . . . pause . . . run, drip, drip, drip . . ."

If you turn off the water upstairs and still have the noise, your home is possessed! RUN!!! RUNNNN!!!!!! :p:cool:

Fencepost
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
Fencepost

It could be thermal expansion or contraction of the bath fan's vent pipe or of a hot water pipe.

alan71
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
alan71

Thanks both Spruce and Fencepost!

Fencepost...regarding the expansion of hot water lines...I have the hot water heater actually turned off; hence I turned the water off along with the hot water heater at the turn off valve to the house. I also drained all the lines...Fencepost..i did not check the upstairs toilet but I flushed it yesterday. we are trying to find out the culprit. we also had the water intake valve replaced about a year ago but it was making the noise before then. hopefully we don't have goblins. LOL:p

alan71
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
alan71
Fencepost wrote:

It could be thermal expansion or contraction of the bath fan's vent pipe or of a hot water pipe.

Fencepost...would the water have to be on to hear contraction of the bath fan's vent pipe? we rarely use this half bath as well. Thanks for all your help! We really appreciate the tips and what to check, etc.

bill
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
bill

i once had a case like this one. it drove me crazy. What i found after after many days was that when you used a fixture you case air flow through the vent pipe which had a depression in it. the depression was filled with water and the air flow caused a small amount of water to be pushed over the edge and this water felled about 10 feet before hitting the drain pipe. and then that made the sound of dripping water. Lesson learned always run your vent pipes with a slope.

alan71
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
alan71

Updated...we just had Roto Rooter inspect our plumbing system and they stated that it was expansion of the pipe rubbing against a floor joist. This was after I turned on the water but he had no explanation for what it was when the water was turned off and we could hear the sound then. I also drained the pipes. It's a mystery but they concurred that it's nothing to be concerned about because if it was moisture getting out then we would have known about it a long time ago. Any thoughts? :)

ed21
Re: Loud dripping sound when water is off/no evidence of water damage-ongoing issue
ed21

I can hear a slight ticking sound from the main supply pipe from the well from rubbing against the joists when the well is pumping. It makes sense since the water is colder than the basement. However it only happens when the well is pumping.
This doesn't sound like your case, but once I was hearing a dripping sound that turned out to be a leaking pipe in a crawl space. I kind of like Bill Shack's sort of explanation of what might be happening. Check that toilet too as explained.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.