I HAVE 2 COMFORT ZONE HEATERS 1 NEEDS REPLACEMENT PART FAN ROLL THING BECAUSE IT MAKES A HUGE RACKET, THE OTHER IS NOT WORKING AT ALL GIVING aos MESSAGE

SOURCE: I have a comfort zone

Unless you want a new house, stop using that heater immediately. There are severe internal electric problems with your heater. Since it's already 3 years old, I'm not sure it's worth trying to repair. With what you described, I'm surprised it didn't trip one of you circuit breakers.

Be safe, Don't continue to try to use this heater.

SOURCE: I bought a Comfort Zone

If it's under warranty, the "hassle of shipping it off is small", compared to possibly doing more damage, while trying to repair it yourself and voiding the warranty. Once they repair it, the warranty starts over again. Just make sure you get authorization from Comfort Zone, before shipping it to them..

SOURCE: My Comfort Zone Utility/portable infrared heater, model CZ1500-WO is displaying an AOS error code and will not turn on. What does that mean and can it be repaired?

If the relays are clicking there is 2 1000 uf capacitors on the board that if looked at from the side they will be domed they are bad. Replace and the problem is solved.