Footer of the first page of every chapter is not bold, but it should be. All the others are bold.
\usepackage{fancyhdr}
\setlength{\headheight}{40pt}
\setlength{\parindent}{0pt}
\makeatletter
\setlength{\@fptop}{0pt}
\makeatother
\renewcommand{\topfraction}{1.0}
\renewcommand{\bottomfraction}{1.0}
\renewcommand{\textfraction}{0.0}
\pagestyle{fancy}
\renewcommand{\chaptermark}[1]{\markboth{#1}{}}
\renewcommand{\sectionmark}[1]{\markright{#1}}
\clubpenalty = 10000
\widowpenalty = 10000
\displaywidowpenalty = 10000
\fancyhf{}
\fancyhead[EL]{\textsc{\leftmark}}
\fancyhead[OR]{\textsc{\rightmark}}
\fancyhead[ER]{}
\fancyhead[OL]{}
\rfoot{}
\lfoot{}
\cfoot{\bf \thepage}
fancyof course, butplain, in a usual setup; your changes are not applied for this first page of a chapter then. You have either to say\fancypagestyle{plain}{\cfoot{\textbf{\thepage}}etc. or using more sophisticated tricks. Side note:\bfis a deprecated macro; use\textbf{...}instead – Oct 31 '17 at 23:10