Obsessive compulsive disorder is a mental disorder that can be very detrimental to the person's life. The disease has two components. First are the obsessions. These are intrusive thoughts and intrusive desires to perform an action. The person that experiences them knows that they are abnormal and does not wish to perform the action. The compulsion is the action that needs to be done t relieve the obsession. The classic example of a pair of obsessions and compulsions is checking a locked door. The person with OCD has an obsession of checking to see if a door is locked. The person may know that the door is locked, but they must check it anyway to relieve the obsession. Your example of changing the TV volume sounds very consistent with OCD. You have both the obsessive and compulsive components there.
The decision to seek treatment for this hinges on how detrimental your OCD is to your life. I think that if the the TV volume is only only OCD example, the it may be silly to seek out care. I would venture to guess that this will not be your only obsession and you may develop more later. If this happens, then I would schedule an appointment with a psychiatrist
that can recommend therapy and prescribe medication that can give you some relief.