I've given my tenant slack because she lost her job. She has two years of paying on time though. I have no obligation to do that. The last tenant I had destroyed my house, cost me $12,000 in repairs, and fled in the middle of the night. It took me a month to enter my own home once the eviction notice was served, despite the fact the house was empty. Your ethical obligation is to provide them with a domicile that meets the legal standards set by your country/locality. Their ethical obligation is to abide by the contract and pay on time. If they are in breech of their end of the contract you have every ethical right to evict them.