Resolved Oasis Flameout error even with flame

[MarkMaxPayne]

I'm on a trip in Central California where the temps are exceeding 100 degrees. Even though I had my Oasis unit go through it's annual service at the dealer back in May this year I'm experiencing flameout errors. The combustion fan starts running, then the igniter starts to glow, then the flame lights. More often than not I then see the flame out red LED light up even though the combustion chamber is all aglow burning fuel just fine, then the flame shuts off about a half second later. It'll automatically make a second attempt, often with the same behavior and result.

When I reset the Oasis I see the same behavior, but after about 3-4 reset cycles the flameout LED doesn't come on while the flame is indeed still burning and things are fine until the next time it acts up.

Any tips for dealing with the flame sensor, other diagnostics, or bush fixes? I am thinking the sensor or control board may be the issue.

Thanks,
-Mark

 

[SteveMA]

Flame sensor carbonized or failure? Sensor has to come up to temp very quickly or system thinks low-temp = no flame. Had similar this over a year ago in a home heater and pulling the sensor wiping it down and reinstalling it cured issue. Mine was dust from non-use, oasis more likely partially burnt fuel. These sensors are known to fail. Normally replaced in annual service i think. Could also be a bad one or loose connection on sensor wire

 

[MarkMaxPayne]

Yeah, after more testing I'm suspecting the flame sensor may be at fault even though the rig is only just over a year old. I pulled it out for inspection and it looked fine. It tested at 1.9K ohm resistance when same as outside temp.

If I reset immediately after 3-4 supposed "flameouts" in a row (flameout LED lights even though there is combustion in the chamber) then the flame finally continues to burn without the flameout LED lighting. I suspect this is because all the combustion reset after reset got the sensor hot enough over time. Once running for real it'll then run as normal until there has been a cooling off period.

Looking at other threads it appears these flame sensors are only available in the 5 year service kit?

Best,
-Mark

Edit: Next post I learn what an igniter is...

 

[MarkMaxPayne]

Okay... Is this where I find out I am an idiot and that sensor I was looking at isn't even the flame sensor? Oops. That's the igniter...

Going to seek a replacement the online pics look like this other sensor... Its sensor looks clean and I used an airhose to blow out the port it plugs into.

Going to hide in shame now and test if that bush fix works as I wait for a spare/place.

 

[MarkMaxPayne]

 Solved. Made a visit to Bish's on my way home to finish up warranty items that they postponed on my trip down (SilverLeaf fix, bad black tank sensor, etc.) Turns out there was debris in the fuel nozzle only a couple of months and 40 hours after my annual service. Although the chamber had a flame in it, the sensor didn't like that it wasn't intense enough.

I have also ordered a maintenance kit online so I have a spare nozzle, sensor, and igniter in addition to a spare fuel filter.

Best,
-Mark

 

[SteveMA]

Thanks for the update Mark. I wonder if there was any visible color difference in the flame through the sight glass pre/post nozzle replacement? (just for future "visual diagnostic" help)

 

[MarkMaxPayne]

Thanks for the update Mark. I wonder if there was any visible color difference in the flame through the sight glass pre/post nozzle replacement? (just for future "visual diagnostic" help)

I cannot tell the difference visually. Looks like the same robust orange flames & glow I saw before. That said, I do think I hear a noticeable difference. It seems louder and more throaty. I just don't think I'd notice on my own though.

Best,
-Mark

 

[newmarokie]

I had a flameout/sensor failure last January. I didn't have spare parts at the time.. Part of my problem was the unit was smoking terribly. I carry a can of brake parts cleaner. I got the nozzle out and backwashed the nozzle with the aerosol cleaner. I reassembled and the failures stopped. I have since stocked the coach with replacement parts. But, the cleaning got me through the weekend.

 

[MemoriesByTheMile]

Confession time - we have only bought one new nozzle in the past few years. Every year I take out the nozzle and clean it with brake cleaner and replace the black o ring on the nozzle. If in a hurry, will swap the nozzle out with the spare, but then clean the “old one” and then put it back in the oasis spare parts bin.
We use the coach half the year, and use the diesel burner roughly a third of that time.
We do replace the fuel filter every year.
I am wondering how many years we can get from a nozzle before it wears enough to be a problem.
One thing I have noticed, if the burner is not used regularly (every month?) it will tend to foul and will need cleaning/swapping out.