Poof and flame from Suburban Water Heater

[Mowalker]

I hope someone here can get us in the right direction. When running the water heater on gas it can be fine for a while (even a day) then out of nowhere when trying to reignite it will keep clicking a few times and then we hear a loud POOF and flame shoots out of the vent.

We have cleaned the burner tube and the dealer has cleaned the burner tube. It is at a dealer (not who we bought it from) for the second time with this issue and they still can not find out what is causing it. Apparently it has not done it while there.

We usually turn it off the gas and end up using it on electric, but will need to run the A/C, coffee maker and other appliances on our upcoming trip.
All other appliances work well on gas (fridge and stove) with no issues.

Any idea what is causing this? What should the dealer (or us) be looking for? How can it be fixed?

Thanks

[CUFFS054]

Sure sounds like "delayed ignition". Usually caused by the spark not close enough to the burner and/or weak spark.

[Mowalker]

Thanks Cuff,

We will be picking it up shortly and will mention this. I appreciate your response

[JRTJH]

Sometimes, when changing a gas bottle, or when first starting the propane system after being shut down for a while, there will be a lack of propane in the lines. Or maybe a better way to state it, there will be too much air in the lines. If you've recently changed propane bottles, had an empty one or maybe just turned the gas back on, it may take a couple of ignition sequences to bleed all the air out of the lines.....

Now, I said this to illustrate yet anyother possibility. You may have your "air mix vent's open too much or possibly a piece of rust on the inside of the propane jet that is partially blocking the propane mix. Sometimes spiders, dirt daubbers, etc will take up residence. Make sure the jet burner, the mixing chamber, the propane jet are all clean. Also, if you can get behind the sheet of aluminum that's blocking the chimney, run a bottle brush through the flue just to make sure there is no buildup in the flue.

[Mowalker]

Thanks JRTJH,

It usually happens after we have been set up for a day or so and not any change over to cause any air in the lines.

Now the "air mix" issue is something I will look into along with any extra cleaning.

Thanks for your reply.