Water pipes sound like they are consistently running in condo

Hey everyone. Thanks in advance for any answers.

I live in a two story condo, on a slab. A week or so ago, I noticed the sound of water running in the pipes consistently. Almost sounds like the water running when someone is taking a shower far away from you in the house. It's not a neighbor, as this is a 24/7 sound now.

I have a water heater in the pantry in the kitchen, and the downstairs bathroom is close-by. You can hear the sound of water running and in both the bathroom pipes under the sink and the pipes over the water heater, a slight hiss every 5-10 seconds.

As I sit in my living room, the sound is just reminiscent of someone running the water in another room. Just the sound of water running consistently. I can also hear the hiss from here every several seconds. Any ideas of what the issue could be?

 

Are you new to this condo? Does it have a hot water circulation system?

If this water sound has never occurred before it is possible there is a water leak somewhere.

 

I purchased it and moved into it in April. The sound started a few weeks ago. As far as a hot water circulation, I believe so, although I'm not entirely sure. All I know is that I have a large cylindrical electric water heater, and I hear the sound of running water through pipes when I get near it, although no leaks or anything like that.

 

Slab leaks happen.

Have you done testing to isolate a possible location of a leak namely turn off the water heater cold inlet for a few hours, then turn off the main cold water shutoff for a few hours, etc?

(This time turn off the water heater heat using the panel breaker before turning off the cold water feed. Turn on a hot faucet and let water run for a minute before turning the water heater power back on.)

Do you have your own water meter? Check it for dial spinning or rotation when "nobody" is using water.

 

If you have your own dedicated water heater and you don't see a small pump on or near it, it's probably not recirculated hot water. You would've heard that from the get-go anyway.

If you can find a time that no one's home, or get everyone to agree not to use the water for a while, you could check the water meter for movement.

If there is movement, check all the toilets with food coloring & repair as needed, then check the meter again.