Zillow Advice: Home Buying - Seller didn't disclose water penetration. http://www.zillow.com/advice-thread/Seller-didn%27t-disclose-water-penetration/507700/ Zillow Advice | Zillow Real Estate Sounds like routine home ... http://www.zillow.com/advice-thread/Seller-didn%27t-disclose-water-penetration/507700/ Sounds like routine home maintenance.&nbsp; An over flowing sink due to a clogged drain is not "water penetration" but more "ooops, I forgot to do routine maintenance". &nbsp; &nbsp;&nbsp; Apparently A/C overflow pipe is clearing something that should go on your home maintenance schedule.&nbsp;&nbsp;&nbsp; I find with each new-to-me house that I have to be very careful to get everything on the list.&nbsp;&nbsp; <br/><br/>Enjoy your new home.&nbsp; <br/><br/> Tue, 20 Aug 2013 15:43:00 GMT http://www.zillow.com/advice-thread/Seller-didn%27t-disclose-water-penetration/507700/ 2013-08-20T15:43:00Z "water penetration" on the ... http://www.zillow.com/advice-thread/Seller-didn%27t-disclose-water-penetration/507700/ "water penetration" on the disclosure form means "from the outside", such as a leaky roof, bad flashing at gutters walls vent pipes and chimneys, bad caulking on windows or window trim or door trim, or water seepage through walls at building foundations.&nbsp; It does not mean "clogged sewer drains" nor other clogged drain lines.<br/><br/>It is your responsibility to regularly periodically clear drain lines.&nbsp; The seller is only required to disclose what they "know" to the best of their ability.<br/><br/>Having water back up on upstairs sinks when the sinks aren't even being used is a bit unusual.&nbsp; Your husband may be right that it is how the condensate drain is tied into your plumbing, and that it is "clogged".&nbsp; But more than a full sink of condensate drain water from only one day of use?&nbsp; Very humid hot day?&nbsp; It still sounds unusual.&nbsp; Why would the downstairs drains work "just fine", but the upstairs drains be "clogged"?&nbsp; The drain water will not go from downstairs to upstairs.&nbsp; Is there a drain screen on the drain line for the condensing unit or air conditioner condensate drain?&nbsp; If not, that may be what is missing and may be what caused the clog.&nbsp; What is the roofing type?&nbsp; Is there a lot of lose aggregate that may have found its way into the drain?&nbsp; Or are birds and squirrels hiding nuts there?<br/><br/>You not only need to have the drain line cleared, but need to find out what caused any clog. Tue, 20 Aug 2013 04:30:00 GMT http://www.zillow.com/advice-thread/Seller-didn%27t-disclose-water-penetration/507700/ 2013-08-20T04:30:00Z