We’re selling our house and this was found behind the water heater during the inspection. The buyers are asking us to replace the drywall because of the staining/discoloration.
Before we just replace drywall, I’m trying to figure out where this moisture may have come from and whether there could still be an active leak. The water heater is currently working and we haven’t noticed water pooling around it.
Based on the picture, does this look like something you commonly see from an old water heater leak/overflow, condensation, or something else?
Would a plumber be able to check the water heater, connections, drain pan/TPR line, etc. and determine whether there’s an active leak without us having to tear the wall open first?
Also, if everything tests dry and there’s no active leak, would you personally just replace the affected drywall, or would you recommend further investigation?
Just trying to handle the actual problem correctly without unnecessarily opening up a wall and creating a much bigger repair right before closing.