Hot water heater not burning right

This thread is a couple of months old but I figured I'd chime in. I had a problem with my Atwood water heater on our Memorial weekend trip. I noticed a whole lot of soot coating the vent and fridge panel above it. The heater had been running for only a few minutes. The flame was lazy, yellow and was visible up to the exhaust side. With guidance from the manual I pulled the burner tube to fine a spider nest flapping inside. I had purchased a small bottle brush in preparation for the job and that did the trick. At first (or second) I thought there was an issue with the propane but there was no change after switching to the new tank so I proceeded to clean the burner tube. Oddly I could not find any posts on RV.net that addressed soot and weak flame from a water heater.

Two Months later, sorry LOL.
Glad it worked out.Thanks for the update.
Most folks don't notice it, if it still heats the water. I see it all the time, if you read the small print, it says "May Contain Propane" LOL.

It was bad fuel. I hooked up another tank and it worked fine. I'm going to take it back to where I got it filled. I had never heard of a bad propane fill, thanks for the heads up.

I would say that if the flame is all orange, there are contaminants in the air or fuel.
That said, there may be a slight orange or red tint in a normal flame usually in the form of streaks. This is caused by dust particles in the air and cannot be eliminated if the air quality doesn’t change. It does not denote any sign of insufficient air supply.

Folks assume that a tank of propane has pure propane in it, but usually it will have small amounts of some other gases that shouldn’t be a problem getting a good flame 99% of the time. Also, let’s assume that you just changed the tank? A tank that wasn’t purged properly could still have contaminants in it that can affect the colour of the flame.

So is it the fuel or air? If it was the fuel, the stove top burner would have an orange flame when the gas from the new tank reaches the burner. If it was the air I would assume that I would notice dust in the air, but maybe not? Could even be CO gas in the air from a vehicle near by running. You don’t mention that this heater is in a motor home? It will also help the members if you let us know the make and model of the HWT.

Good Luck

I watched videos online and no matter how I slide piece to give more or less air it never turns blue. I took it apart and and made sure there was nothing blocking any of the tubes and it is fine. Any other ideas? The RV places here are so expensive I really hope I can fix it myself.

Usually if it was burning right previously, it is just a spider web (or nest) in the mixing tube.

Common problem. (If I explaned it with my writing you'd be more messed up) Go to youtube and do a search on rv hot water or tune up hot water heater or similar. They go thru step by step. You need nothing more than a good cleaning and air adjustment tube needs adjusted. Then after you get this fixed, do it every year to keep in adjustment and prolong life of heater. Takes about 10 min after you get the swing of it.

After making sure the burner tube is clean there is a slide adjustment on the burner tube it is held by a small screw loosen this screw and slide the adjustment sleeve one way or the other till you get a blue flame with just a small yellow tip.

A couple of air blasts to the burner area from my compressor fixes mine right up.

Clean the burner area, spiders often cause problems in LP appliances.