Electrolux Gas Fridge Increasingly Hard To Light

[DandV]

We had two of them running on the NZ LPG mix  (approximately 60% propane 40% butane) Lighting them after any prolonged shutdown was always a slow process. Ten minutes or more of holding down the top button then pushing the bottom button. After a while you would at least get a pop but several more attempts whould be required to get the top button to latch. I put it down to that, Ignition will not occur until every last vestige of air is eliminated from the supply pipework and secondly the heat sensing latch deteriorates with age requiring a longer heating period. Good luck. One 20yr old fridge had got to the stage when we doubted that it would ever light.

Time then for a solar power installation.

[alan_fincher]

Although the boat with the fridge that first prompted this thread has long since been sold, its replacement also has an Electrolux gas fridge with Piezo ignition.

It is never as hard to light as the old one, but can still sometimes be temporarily temperamental.

It is much easier to get at to see what is going on than the old installation.

The flue pipe is completely clear, and there is are spiders or other crap in the burner, but it will regularly "pop" but not ignite.

However if I release the burner out of its cradle, and drop the whole assembly a few centimetres away from the flue pipe, it fires first time, and stays alight perfectly.  Put it back again, and it can't be guaranteed to light first time, even when it has done moments earlier in "stand alone" mode.

I can always see I never ever fail to get a spark when the button is pressed, (at least whilst it is not in the flue).

My conclusion is that in our case, the difficulty in lighting has little to do with air in pipes, muck on burner, or anything wrong with the flue.  Also the piezo spark generator actually seems 100% reliable. It simply seems to be the fact that you are releasing the gas into the flue and trying to light it that results regularly in the case it goes "pop" but doesn't actually ignite.

(Others may of course be different!)

 

[DandV]

11 minutes ago, alan_fincher said:

Although the boat with the fridge that first prompted this thread has long since been sold, its replacement also has an Electrolux gas fridge with Piezo ignition.

It is never as hard to light as the old one, but can still sometimes be temporarily temperamental.

It is much easier to get at to see what is going on than the old installation.

The flue pipe is completely clear, and there is are spiders or other crap in the burner, but it will regularly "pop" but not ignite.

However if I release the burner out of its cradle, and drop the whole assembly a few centimetres away from the flue pipe, it fires first time, and stays alight perfectly.  Put it back again, and it can't be guaranteed to light first time, even when it has done moments earlier in "stand alone" mode.

I can always see I never ever fail to get a spark when the button is pressed, (at least whilst it is not in the flue).

My conclusion is that in our case, the difficulty in lighting has little to do with air in pipes, muck on burner, or anything wrong with the flue.  Also the piezo spark generator actually seems 100% reliable. It simply seems to be the fact that you are releasing the gas into the flue and trying to light it that results regularly in the case it goes "pop" but doesn't actually ignite.

(Others may of course be different!)

 

With that information I suspect the problem is that the area above the burner, ie the bottom of the flue, is easily taken into a state above the upper flammable limit, that is too rich to support combustion. The lower and upper limits flammable limits for propane are 2% and 10% by volume so quite a narrow range. The limits for butane are even lower.

[alan_fincher]

9 minutes ago, DandV said:

With that information I suspect the problem is that the area above the burner, ie the bottom of the flue, is easily taken into a state above the upper flammable limit, that is too rich to support combustion. The lower and upper limits flammable limits for propane are 2% and 10% by volume so quite a narrow range. The limits for butane are even lower.

That may well be the case.  I can only report what I found by practical experimentation, not necessarily accurately conclude the reasons.

What isn't explained though is that if we assume such a fridge once lit OK, without a fight, what has changed to bring about less chances of instant success?  The gas or the pressure it is supplied at should have remained constant, so one assumes some other parameter has changed.

[nicknorman]

46 minutes ago, alan_fincher said:

That may well be the case.  I can only report what I found by practical experimentation, not necessarily accurately conclude the reasons.

What isn't explained though is that if we assume such a fridge once lit OK, without a fight, what has changed to bring about less chances of instant success?  The gas or the pressure it is supplied at should have remained constant, so one assumes some other parameter has changed.

I don't know much about Electrolux fridges but have had a few issues with my caravan fridge which is a Dometic, modern one with auto-ignition. It kept on failing to auto-light and transpired it did light but the flame detection system thought it wasn't lit and locked it out.  I couldn't see why it wasn't detecting the flame. I messed about with it for ages. Fortunately I was chatting about it to a fellow glider pilot who was also a caravan service chap. He said it would be slight corrosion in the mild steel burner tube. Later models had a stainless steel burner as it was a known problem. The burner tube did have some mild surface corrosion but nothing flaking off, and even after I took it off and cleaned it up it still didn't work. I duly replaced the burner tube with a new one and now it is perfect. So my conclusion is that the slightest blemish on the burner or similar can upset the gas flow much more than one might expect.

[alan_fincher]

Which would of course be an explanation about how one can get slowly worse over time, even if it looks visually OK.

Thanks, Nick.

[Ex Brummie]

 

4 hours ago, alan_fincher said:

What isn't explained though is that if we assume such a fridge once lit OK, without a fight, what has changed to bring about less chances of instant success?  The gas or the pressure it is supplied at should have remained constant, so one assumes some other parameter has changed.

A warm flue will draw the gas, allowing fresh air to mix to a favourable level for ignition.