Suburban water heater - adjusting flame

[George Schweikle]

My suburban water heater is running too rich; the flame has a lot of yellow, and there is a definite smell and some sooting on the cover panel vent area. The owners manual doesn't have anything indicating an adjustment process, and I don't see anything that looks adjustable on the actual unit.

Has anyone else been confronted with this problem?. Did you find a solution? (I didn't see anything under "search").

[PlayItForwrd]

somewhere on the aluminum tube leading FROM the burner TO the propane nozzle you should find a square hole in the tube, with a sleeve around it. This hole is to venturi-feed air into the propane stream. you rotate the sleeve to make the hole larger or smaller, which adjusts the burn. Lots of yellow means you need more air. The hole is also great for spiders and wasps to get in and lay eggs & such, otherwise plugging the tube. If the hole is nearly full open and your flame is still rich, check the tube for obstructions...

[George Schweikle]

Thanks, you described just what I was looking for; a way to vary the air in relation to the fixed propane flow. However, there is no hole or adjustable sleeve; in fact, no adjustable nuthin'. The water heater is a Suburban SW-6D in a 1999 Safari TREK, and the tube is zinc plated steel with what looks like a crimped - in venturi, and appears clear of obstructions. The previous owner used this RV for 10 years, and just put up with the issue. I have an appointment in 2 weeks at my local RV service shop, and will post results.

Originally Posted by PlayItForwrd

somewhere on the aluminum tube leading FROM the burner TO the propane nozzle you should find a square hole in the tube, with a sleeve around it. This hole is to venturi-feed air into the propane stream. you rotate the sleeve to make the hole larger or smaller, which adjusts the burn. Lots of yellow means you need more air. The hole is also great for spiders and wasps to get in and lay eggs & such, otherwise plugging the tube. If the hole is nearly full open and your flame is still rich, check the tube for obstructions...

[DAN L]

Originally Posted by George Schweikle

Thanks, you described just what I was looking for; a way to vary the air in relation to the fixed propane flow. However, there is no hole or adjustable sleeve; in fact, no adjustable nuthin'. The water heater is a Suburban SW-6D in a 1999 Safari TREK, and the tube is zinc plated steel with what looks like a crimped - in venturi, and appears clear of obstructions. The previous owner used this RV for 10 years, and just put up with the issue. I have an appointment in 2 weeks at my local RV service shop, and will post results.

http://www.bryantrv.com/docs2/docs/o.../swinstall.pdf
look at page 6, figure 12 for air adjustment on the sw-6d water heater.

[George Schweikle]

DAN L,

Thanks. I also saw this figure in my manual, but my water heater doesn't seem to have anything that looks like the air shutter in the diagram. There's a very small "Ring" right at the entrance to the tube, but it doesn't appear to be capable of changing the air flow if moved. And, it appears to be staked, welded, or rusted in place. I will check at the local RV dealer & see if they have a new burner tube in stock; maybe that will have an air shutter.

Originally Posted by DAN L

http://www.bryantrv.com/docs2/docs/o.../swinstall.pdf
look at page 6, figure 12 for air adjustment on the sw-6d water heater.

[Robs]

Erratic main burner flame sputtering yellow:
1) Incorrect gas pressure - check for correct gas pressure coming through main burner orifice; should be 11 " WC.

(Replace regulator if less than 11 " WC.)

2) Check for blockage or obstruction in main burner orifice. Remove and clean with alcohol and compressed air. Do not enlarge orifice hole. Clean main burner if necessary.

(Replace orifice if it can’t be cleaned do not use a drill bit to clean it out)

3) Misalignment of main burner - check for correct alignment.

4) Burner flashback - check main burner orifice. Must be properly seated into main burner - (straight in line with tube).

5) Sooting - can be caused by thermostat not shutting off completely or other obstructions or blockage in flue box.

If you need the service manual message me

[George Schweikle]

Thanks Robs,

I discussed the issue with the RV service manager today, and have an appointment next week for them to look at the problem. He suggested hosing out the burner area, which I did and got a lot of soot, but the yellow tip flame still persists. Checking gas pressure and regulator function is something the shop must do since I don't have the equipment.

Intuitively, the problem is either too much propane, or too little air; causing a "rich" mixture at the burner. There doesn't appear to be any adjustment in air, main burner position, or burner orifice. We're off on a spring trip; I will report after the shop does their analysis and maybe help someone else who may have the same problem.

Originally Posted by Robs

Erratic main burner flame sputtering yellow:
1) Incorrect gas pressure - check for correct gas pressure coming through main burner orifice; should be 11 " WC.

(Replace regulator if less than 11 " WC.)

2) Check for blockage or obstruction in main burner orifice. Remove and clean with alcohol and compressed air. Do not enlarge orifice hole. Clean main burner if necessary.

(Replace orifice if it can’t be cleaned do not use a drill bit to clean it out)

3) Misalignment of main burner - check for correct alignment.

4) Burner flashback - check main burner orifice. Must be properly seated into main burner - (straight in line with tube).

5) Sooting - can be caused by thermostat not shutting off completely or other obstructions or blockage in flue box.

If you need the service manual message me