The use of the words equity release are confusing.
You can get an equity loan which is basically increasing your mortgage to the value of the property i.e. after say 3 years the house has increased in value, you could in effect borrow that money.
Equity release schemes which are aimed at the older market is where you take X amount out of the property but you dont make any payments, its assuming you will pop ya clogs in the next 10-20 years but interest is accrued on the money. In recent years the law has changed and I dont think it can be more than 50% of the amount borrowed.
You should first have a chat with an independant financial advisor. You would also need to speak to your lender because some will not let you rent out a property. (if you have tenants in and fell behind with your payments then the lender would struggle to repossess the house).