Hot water heater

[Inspector]

Need some help. We have a 2020 3121rl. We bought it in September 2019. In November 2019 we took it out for a few days to learn how to use it and everything worked great. In December, we had it winterised. In late April we had it dewinterized and took it out in May to make sure everything was working correctly. I run water through the rig for a long time to flush the antifreeze on cold and hot. I put the hot water heater on propane like I did in November. In November the hot water heater worked great. This time the hot water heater started blowing fire on the outside of the unit after about 30 to 45 minutes. We have had it in a repair facility since then and have not received any results to getting it corrected. When this first happened I notified the insurance company and the manufacturer. Not much damage was done because the fire was caught quickly. I have a report that the water heater was filled only to about 80 percent at the time of this incident. Would that cause the fire? I would not think so because it was blowing fire from the outside of the rig. When the propane was cut off the fire stopped. Anyone have any thoughts. We are wanting to hit the road and travel but we are on hold. I am willing to pay for the repairs if I did something wrong. Right now I can’t get any answers. Thanks.

[prndl]

just my opinion but...
If you paid to have the trailer de-winterized that would have included flushing the anti freeze from the system. That is pretty much what a de-winterizing includes.
If someone said (THE REPORT) you only had the water heater filled 80%, were they there when it happened? I don't know how in the world anyone can calculate 80% filled of the water heater. When it got back to the repair shop who knows how much water was still in the tank and how does that relate to how much was there when the incident happened? How could a partially filled water heater cause flames to come out of the side?
If you are blowing flames out of the water heater there could be any number of things causing that some like insects building nests in the vents, others might have more information.
Someone is trying to pull the wool over your eyes.

[RMcNeal]

On our previous TT SOB I had a spider web, very large one, inside the furnace that caused flame to shoot out of the exhaust port when it ignited. It only lasted a few seconds until the web was burned up, but it scared the bejeezus out of us. I wonder if something like that could have happened to your water heater.

[BB_TX]

I would be a little suspicious that who ever did the dewinterizing did something to the water heater. The water level would not affect the flame. I would say to remove the cover to the WH and check it out, maybe post pictures on here for all to see. But since it is at a dealer you can't do that.

Dealers are notorious for being slow with service. Sometimes a mobile RV tech is a better option for minor issues.

[Montana Man]

If you have hot water, why do you need a heater?