Atwood WH at 8000 Relights Frequently

[KJRitchie]

I'm at Bryce NP around 8000ft altitude. I've noticed my water heater relights frequently. It starts and sounds normal, a good burner roar, but after a minute or so the roar quietness down and the flame extinguishes. Then about 10 seconds later the water heater will start up again. I've tried opening the adjustable slider on the burner tube to the maximum opening but it still doesn't help.

With the door open it seems to stay lit. I also notice with adjustable slider open at max placing my finger on the opening I can hear how the flame changes from loud roar to a muffled sound but it doesn't extinguish because the panel door is open.

I'm assuming with the panel door closed the burner starts and runs well but starves itself of oxygen within a couple of minutes.

No evidence of obstructions.

Any suggestions for improving high altitude performance other than keeping the access panel open?

Kelvin

[KJRitchie]

I'm now at Heaton Bay COE campground at 9000 ft and the water heater is operating normally.

Kelvin

[cwf]

Sounds like you were burning out restrictions. Either in Gas or burn tube...

[ghaynes755]

Kelvin what was the outside air temperature at both locations? Maybe, not likely but maybe, low pressure from overnight cooling temps and then as you changed locations sun radiation and air temps increased.

[JCWDCW]

I think reduced air pressure at high elevations is just starving the burner. Opening the door lets it breath a bit more. If the flame is not hot enough then the flame sensor will shut down the burner. If you open the primary air collar too much the flame will run hot at the end of the flame but the extra air will cool the middle of the flame where the sensor is usually located, so be careful to open the collar just enough to leave a very small flicker of yellow in the flame tip. Generally if the primary air is open too much the flame will 'burble' and flutter. That will take a toll on the sensor and spark plug electrodes.

Also if it is cold the gas pressure may not be high enough as the propane won't evaporate fast enough to deliver full pressure to the regulator.

JCW

[HowieE]

I would look at the flame and see if it is touching the proof of flame element. The altitude may have changed the flame formation to a point that the heater is going off because it is not seeing proof of flame but is reigniting against the thermistors.

Unless you are going to stay there for a while I would not make any changes, the water will get hot it will just take a while.

[bwoodtx]

If you have the electric option on the water heater use that. Or if you do have that turned on, that could be why the propane side is short cycling.