Thanks @Ryan Short and @Rich Ng.

I have an upper unit of similar size, poorly insulated, that has no returns, and has been a bear to heat with NG forced air.

Two family members experienced L O N G delays getting buyer financing in Calif. 

@Albert Ng, I know this is an old thread but came across it somehow. 

@Alvin Ng Once you bought the property the rent due is yours.

NG allows the tenant to call before 5pm on any weekday and transfer responsibility that same day.  

I converted several of our rentals to on-demand NG to cope with hot water demands & CO safety issues.

@Michael L., at the end of the day you must do what is right for you. 

So last week I closed in this SFH in Kissimmee Florida, Lats time I talked to the seller he said that the tenant is his sister and he doesn't have a lease agreement with here and I can raise the rent as soon I buy the property . she is paying 695$ and the market rent is 1200, after closing I went to the house and meet the tenant and told here that we will be raising the rent to to market rent ... she refused and asked me to wait  6 month until she find another place and not changing the rent... 

@Albert Ng You have to make a good faith effort to find the delinquent borrower, to serve them with the foreclosure action.