What does char 160 mean in my source code?

Question

The answer is to look in Unicode Code Charts - where you'll find the Latin-1 supplement chart; this shows that U+00A0 (160 as per your title, not 167 as per the body) is a non-breaking space.

char code 160 would be  

Maybe you could to use a regex to replace those empty chars:

Regex.Replace(input, @"\p{Z}", "");

This will remove "any kind of whitespace or invisible separator".

value.Replace(Convert.ToChar(160).ToString(),"")

This is a fast (and fairly readable) way of removing any characters classified as white space using Char.IsWhiteSpace:

StringBuilder sb = new StringBuilder (value.Length);
foreach (char c in value)
{
    if (!char.IsWhiteSpace (c))
        sb.Append (c);
}
string value= sb.ToString();

As dbemerlin points out, if you know you will only need numbers from your data, you would be better use Char.IsNumber or the even more restrictive Char.IsDigit:

StringBuilder sb = new StringBuilder (value.Length);
foreach (char c in value)
{
    if (char.IsNumber(c))
        sb.Append (c);
}
string value= sb.ToString();

If you need numbers and decimal seperators, something like this should suffice:

StringBuilder sb = new StringBuilder (value.Length);
foreach (char c in value)
{
    if (char.IsNumber(c)|c == System.Globalization.NumberFormatInfo.CurrentInfo.NumberDecimalSeparator )
        sb.Append (c);
}
string value= sb.ToString();