We have an intermittent fog horn sound in the wall in our first floor. We can hear it throughout the house and even outside, but it is loudest on the first floor, between the laundry room and the bathroom. We have tried turning off the A/C, turning off toilets, etc. We can't pinpoint what is causing the sound. It appears to be random-not associated with running water, lasting for 15 seconds every 5 to 10 minutes.
This started last night and I'm not sure we are any closer to knowing what is causing it. It isn't related to an A/C turning on, or any faucet, washer or toilet being used. We have turned our water heater to vacation setting, but that hasn't helped yet but we only did this a few hours ago.
Is there anything else we should try?
Thank you for the help.