Why has my blower stopped working? Holly July 26, 2021 08:38 Updated Follow Please Note: If your blower has failed, one of the main causes is a defective non return valve and you should consider replacing that. It will stop the water from slugging the new blower. Related articles Chemical Quick Start Up Guide ML400 User Guide How does a spa blower work? What information do you need to replace my blower pump? Comments 0 comments Article is closed for comments.