If one of our Tier 4 engines is not running hot enough- for instance if the load on the generator is not sufficient to burn all the fuel and clean the exhaust as per design, then the unit may call for regeneration. This causes a red light on the dash panel to blink indicating that a regeneration is needed. To perform this function the unit will need either the breaker opened or the service valve closed and the regeneration button pushed until the light remains solid. The process will generally take 30-45 minutes and the unit will be unusable until the process has finished. Once the Regeneration light has disappeared the unit is ready to function normally again.