I've seen some other questions about dripping sounds but wasn't sure if my situation fills the same circumstances or not.
I have a 2-story home and only a partial understanding of where the mechanisms of HVAC and plumbing are run.
In a wall that is nowhere near the exterior walls of the home, we're hearing a intermittent dripping sound and yet not seeing any damage (yet) nor would we prefer to wait for visible damage before addressing it.
The wall/ceiling where we hear the sound is near the upstairs shower/tub combo. There is an access panel into the back of the tub and yet when we listen there the drip sound is not audible nor is there anything obviously/ominously wrong to my eyes — despite being roughly in the same location.
I've heard and read on this site that warming/cooling hvac or plumbing runs can produce this "drip-like" sounds so am hopeful for this outcome but don't know how to confirm.
We've lived here for 5 months (starting in the heat of summer) and only noticed this sound in the past 3 days in the beginning of Winter — but our heat has been running off/on for a month or so.
Before we heard (noticed?) the sound, we turned off the water to install a new valve fixture on the first floor. Did something shake loose with the sudden change in the status-quo of the normal, pressured environment?
What contractor can tell the difference between normal water dripping inside a pipe versus outside versus condensation versus rubbing sounds of metal on wood? Who would you call first? A plumber or HVAC or "handyman"?
I've tried to isolate by closing drains on sinks and shutting off water to toilets but still haven't figured out what could stop the sound / behavior.
Thanks for your thoughts and perspective!
Update
It still isn't clear to me the right kind of contractor to confirm what I found, but during periods of inactive furnace activity, the sound seems to die down. Also, when I place my ear next to the cavity (firmly against the wall) the sound transforms from dripping to ductwork creaking / popping and I can hear the sound of air being moved.
I'm hopeful that there is nothing to it and that I can come to peace with the red herring sound. My ambition will be to present this as the answer to my question if an HVAC person can confirm it unless someone else can recommend something better. Thank you.
Best Answer
You could have an HVAC condensate drain that is dripping into a vent stack pipe for your waste plumbing. They (HVAC installers) are not supposed to do that, the condensate drain is supposed to run to the outside of the house in a dedicated line. But I've seen several cases where that was not done and the lazy HVAC contractors just put a Y fitting on a nearby vent stack and run their condensate drain into it. There are potentially serious problems with that because sewer gasses can get sucked into the HVAC system. That's why waste vent pipes extend all the way up to the roof.