Your boiler restart button, also referred to as ‘lock out’, is located on your boiler burner unit. Usually, the burner unit front door cover will need to be removed to gain access to the control box reset (when ‘tripped’ the button is normally illuminated). To initiate a start-up, simply push the reset button – always refer to your manufacturer’s instructions for how many times you can safely use the reset button (normally this is a maximum of three attempts).