Could this ExecuteScalar call be written better?
public bool CheckSomething(string paramA, int paramB)
{    
    using (var conn = new SqlConnection(".."))
    using (var comm = new SqlCommand("", conn))
    {
        conn.Open();
        object noOfRecords = comm.ExecuteScalar();
        return noOfRecords != null;
    }
}


There is no need to close or dispose, the using handles that part.  This removes the need for a manual try catch or closing logic, leaving a much compressed chunk of code that is functionally equivalent and just as safe.

As for the select statement itself, either use parameterized SQL or a stored procedure as opposed to string concatenation.  Parameterized SQL:

string sql = "SELECT ColumnA FROM OurTable WHERE ColumnB = @param1 AND ColumnC = @param2";

using (var comm = new SqlCommand(sql, conn))
{
    comm.Parameters.AddWithValue("@param1", param1);
    comm.Parameters.AddWithValue("@param2", param2);

    conn.Open();
    // etc...
}