Corsair confirmed that some of its Hydro Series H100 watercooling solutions have fan controller issues. The company says the problems are limited to units with lot code 11359403, details on how to fix the issue can be found at Corsair.

We have seen a number of posts by people who are having problems using the fan controller on their H100. If you are having similar problems, this post will give you some guidance on how to get the issue resolved.

First of all, we have posted an article on our web site about the H100 performance profiles and how they are used. You can find this article here.

If you are convinced the performance profiles are not working correctly, please read the following:

We have identified an issue with some of the components included in a small number of H100 units with lot code 11359403 only. You can find your lot code on the printed label on your H100 box. If you have this lot code, test your installed unit while the system is running by pressing the profile change button. If you push the profile button on the top of the cooling unit and the indicator lights change, but the fan noise remains the same, we recommend contacting Corsair technical support at ramguy@corsair.com to arrange for some replacement parts that will correct this problem.

However, if you push the profile button on the top of the cooling unit and the indicator lights DO NOT change, you may try one of two steps:

You can reset the firmware on the unit, which in many cases will solve the problem, or
You can contact Corsair customer service and arrange for an advance replacement (credit card required) of your unit.

To reset the firmware, use the following procedure:

1. While the computer is running, hold down the profile button for approximately five seconds
2. Wait one minute, while the unit continues to run
3. Shut down your computer
4. Press and hold the profile button for five seconds while turning on the power to your computer.

If resetting the firmware does not fix the issue, or if the issue re-occurs, please contact customer service to arrange for a replacement unit. Begin this replacement process using the RMA Link that is on the left sidebar of every forum page.