Hi Jim, it's Jack at Dyson.
DC28's on/switch and height selector pad are designed to flash in different combinations to alert you to any issues with the machine. If the on/off button is flashing red and no other lights are displayed, this suggests something is jamming the brush bar:
To resolve this, please clear any obstructions from the cleaner head, and remove any threads or hair from around the brush bar. Our video guide shows you how:
If you need further advice after giving this a try, just get in touch with the Dyson Customer Helpline by calling If you'd like any further guidance after you've given this a try, you can reach our experts directly by calling the Dyson Helpline on 1-866-693-9766 (US), or 1-877-397-6622 (CA).
If a repair or a replacement part is needed, we'll be able to provide further information about this, and to confirm whether or not this is likely to be covered under your free 5-year Dyson parts and labour warranty.