I bought these heaters expecting the controls to be the same as earlier models, where one is able to adjust the fuel air mixture to achieve a lean clean burn. Not only is that not possible, there is no adjustment possible at all. It is supposed to have an automatic altitude adjustment, but it doesn't. It says either 0000m or 0001m. For reference, I am not at sea level here, I'm at 310m.
Additionally, the fuel pump has failed. It sucks air, adds air bubbles to the fuel going into the heater.
I have repeatedly tried to get some sort of refund from Vevor, but their system does not receive messages. I have tried to post messages multiple times, they just don't go through. It has been like 10 days so far, no response. My messages don't go through when I post them.
So now, I'm spending $60 to buy a whole new control set from a different company, the older style where one can control the air/fuel ratio and which can be controlled by aftermarket controllers like the Afterburner.