I am remodeling a powder room on the first floor, and the supply pipe to the toilet broke (old and just snapped at the valve). I turned off the water main and had the valve replaced the following day by Horizon serivces (a plumbing company). Main valve is opened back up. The toilet is not yet hooked back up in the powder room, but when we flush the upstairs toilets, there is a vibration throughout the house that lasts 15 seconds or so and then stops. I've flushed the toilets 10+ times since the fix, but vibrations continue. Doesn't seem to happen with the sinks. Ideas to how to stop the vibrations?