Is Congenital heart disease hereditary?

congenital just means "present at birth" it doesnt mean its hereditary.

most cases the cause is unknown but there is some evidence there may be a hereditary aspect in come cases

Yes. The clue is in "congenital"
possibly.

congenital means "present at birth". although a person is born with it, it may be a birth defect, or a genetic anamoloy, as opposed to an inherited condition.

conditions can be hereditary and congenital, or hereditary and non-congenital, is as much as they dont present until after birth.
It may be genetic/hereditary yes, but doesn't mean you will definitely have it if your mother/father does.

Congestive Heart Failure sounds similar, but means something totally different. I am thinking this is where your question comes from since I used to get a bit confused with the 2.
There may be some hereditary factors that play a role in congenital heart disease. It is rare but not impossible for more than one child in a family to have a congenital heart defect.
congenital heart disease can be caused by heredity, medications, rubella, and diabetes.
This is known as congenital cardiac anomaly. I agree with "top_cat_". An anomaly that is congenital means that it is present at birth. These anomalies can be hereditary and thus genetic but they can also NOT be hereditary and can be due to environmental factors both in utero and ex. Hereditary anomalies are not always passed on. If you need more information about genetic disorders, I suggest you speak to a Genetic Counselor.