Thetford 3 way fridges

We have an autosleeper with a Thetford 3 way fridge. Over the last 2 years we have been having on going issues with dust getting into the pipes supplying the gas to the flame. This causes the flame to reduce and eventually die out.
We were advised to turn the fridge off when travelling over metal roads and to be mindful where we park. ie. not close to a dusty road. Given we kiwis like to go "Off road" a lot, has anyone else had similar issues. We have been advised to replace the Thetford with a Dometic rated for the tropics, but would this  solve our issue.?
Love to hear from any kiwis with similar issues. I know there are some out there with Auto Sleepers.
Jean

I'm struggling to understand how dust could possibly get into the gas supply pipe. It should be gas coming from a gas bottle through a sealed system.  I would first suspect that the gas is from a contaminated source.     Keith

It sounds as though you are suffering from dust getting into the flue chimney above the flame and dropping onto the jet. All I can suggest is that you periodically remove the lower vent and check the gas jet for accumulated dust which can be removed with a vacuum cleaner.

IMO you would have to have a colossal amount of dust in the flue to overwhelm the burner. The usual layout is that the jet is at the far end of a mixer tube - so typically the jet is more than an inch away, below and to one side of the burner. The burner itself has a large opening which dust would be very unlikely to block - unless there was a pile of it on top.

The literal wording that they have used is "dust getting into the pipes supplying the gas to the flame".

As Keith says, if that means dust getting into the supply before the jet, it's contaminated gas, not road dust.

They may mean dust in the mixer tube instead though, as that has an opening at each side to admit air.

I don't know the Thetfords, but if they have the same design as the Electrolux and Dometic burners, a far more likely explanation is rust flakes forming inside the mixer tube. If so, the type of road you travel on is irrelevant.

tikiti wrote:
We were advised to turn the fridge off when travelling

You should not be using it on gas while travelling anyway. If you're using it on 12V while travelling, that won't change the amount of dust getting in it - so that advice does not seem to make any sense at all!