What can you ask seller in terms of property repairs?

[Amanda Smith]

I have an accepted offer on a duplex. When doing the inspection the tenant said not long ago there was water in the basement up to her ankles but was fixed recently. Nothing about this was mentioned in the condition report. I called the water department and the last water bill was normal but prior to that was unusually high for at least 6 months. It was more than double what it should be. Before this, I had asked the sellers agent for the water bill but they had refused to give it, saying the seller has already gone 'above and beyond' because they gave me some rent receipts and saying seller does not keep good records. I asked the city if any permits were pulled or inspections done in regards to the water and they said no. What I would like is for them to let me know what the issue was and how it was fixed. I would also like the name of the company who fixed it to make sure it was done properly. The seller often does repairs himself and this seems like something that would need to be professionally done. Is this too much to ask before I put my money down? 

[Amanda Smith]

There was 3 offers and they chose mine. Yesterday the underwriter saw that the appraisal mentioned basement walls were wet so they are demanding a qualified person to analyze the basement. Hopefully that will get answers for me!