Question: Can a web host access my dedicated server?
Answer: Yes, your web host can probably access your server if it is a VPS. If your server is a dedicated server than your web host maybe able to access it if your web host has set it up so they have access to it. Most of the time a dedicated server that is secure properly won’t be accessible to your web host unless you give them the credentials to login. Your web host may of installed their login credentials to login to the server for technical support reasons. You would have to examine the server to see if anyone else has been added as a user besides your own users.