<p>I dont want the part cooling fan on during preheat, especially when I'm only heating the bed, it is just unnecessarily loud and serves no purpose at that time.</p>

<p>However when I set <code>PREHEAT_1_FAN_SPEED</code> to 0 it has no effect, the fan still spins at full speed as soon as I preheat either the hotend or the bed.</p>

<p>So why is this setting not working and how do I fix this?</p>

<p>I am using the latest version of <a href="https://github.com/MarlinFirmware/Marlin/tree/1.1.x/Marlin" rel="nofollow noreferrer">Marlin</a>.</p>

<p>The only one that is defined is the one that I am editing and it is the one that appears on line ~1260 of the stock configuration.h</p>

<pre><code>#define PREHEAT_1_FAN_SPEED 0 // Value from 0 to 255
</code></pre>

<p>And this is the grep result of searching the entire firmware folder:</p>

<p><a href="https://i.stack.imgur.com/dJh5p.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dJh5p.png" alt="grep results"></a></p>

[{'answer_id': 7850, 'author': '0scar', 'author_id': 5740, 'author_profile': 'https://3dprinting.stackexchange.com/users/5740', 'pm_score': 0, 'selected': False, 'text': '<p><em>This answer is now obsolete now that the OP has updated the question with additional information. It is left here as a possible solution for those who have tinkered with there firmware.</em></p>\n\n<hr>\n\n<p>Part cooling fan speed during preheat (from menu) is controlled by the setting </p>\n\n<pre><code>#define PREHEAT_1_FAN_SPEED     0 // Value from 0 to 255\n</code></pre>\n\n<p>in <a href="https://github.com/MarlinFirmware/Marlin/blob/1.1.x/Marlin/Configuration.h" rel="nofollow noreferrer">Configuration.h</a> where a value of <code>0</code> implies no rotation, or 0&nbsp;% and <code>255</code> implies 100&nbsp;%.</p>\n\n<p>If changing this value in your configuration does not result in a reduced fan speed, you could have this constant be defined somewhere else overriding this value.</p>\n'}, {'answer_id': 7851, 'author': 'cds333', 'author_id': 13829, 'author_profile': 'https://3dprinting.stackexchange.com/users/13829', 'pm_score': 2, 'selected': False, 'text': '<p>Apparently, I forgot a critical step:</p>\n\n<p>While I have completely reconfigured the LCD menus, setup custom 25-point mesh leveling, changed a bunch of other numerical values, and flashed the firmware dozens of times, certain values will never be updated unless you remember to <strong>initialize the EEPROM</strong> after the flash! </p>\n\n<p>Honestly I kinda wish they would make it all or nothing but I guess there is limited space so particular things take priority.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/7847', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/13829/']