Image forming apparatus with setting of an operating condition of at least one image heating device

A image forming system comprising:

• a image forming device for forming a toner image on a recording material;
• a first image heating device for heating the toner image on the recording material at a first nip, said first image heating device being heated by a first heater so as to maintain a target temperature;
• a second image heating device for heating the toner image on the recording material, which has been heated by said first image heating device, at a second nip provided at a position is different from the first nip, said second image heating device being heated by a second heater so as to maintain a target temperature;
• a selecting device for selecting one of image forming modes including a first image forming mode in which only said first image heating device is used for a image heating process and a second image forming mode in which said first image heating device and said second image heating device are used for the image heating process;
• and
• a delaying device for making timing at which the target temperature of said first image heating device is lowered in a stand by state later than a timing at which the target temperature of said second image heating device is lowered in the stand by state.