Oil fired Rayburn persistent fumes after service.

[Isaac]

Firstly, don’t be tempted to use exhaust paste on the burner shells - they are virtually impossible to clean properly after it has been applied.

Good, that was my gut instinct too, sounded too much like a bodge to me.

I don’t normally like to propose trial and error solutions - but it may be worth trying the range without the restrictor plate in place, or if you can with it partially removed.

I've added some extra rope seals, just to keep the unpleasant smell down whilst I experiment (and until the chimney sweep gets here). They seem to be working. Another windy day and again the smells went away. I don't know though whether that's how the burner normally smells and its the flue not taking the gases away that's the problem, or whether there's something wrong with the burner and having a more effective flue is just masking the problem. Anyway, thanks again for all you help, it's been invaluable.

 

[Brambles]

Isaac,

I think that you have two issues, worn set if burner shells and a flue that has probably slightly light on draw.

If you can improve the draw on the flue by increasing the holes in the restrictor plate you will get a resolution. If the draw is too great you will see the flame picture change - so reduce it and / or slightly increase the oil drip rate.

Not much you can do with the burner shells as they wear (just nurture them) better to put your efforts into sourcing a spare burner set.

If it is any consolation, I spent six hours yesterday afternoon, fine tuning a flue with a restrictor plate on an Aga after it (the flue) had been disturbed during cleaning! They are very sensitive creatures! Had I not know the owner well, I would have felt embarassed.

 

[Isaac]

I spent six hours yesterday afternoon, fine tuning a flue with a restrictor plate on an Aga after it (the flue) had been disturbed during cleaning!

Oh no. If it took someone like you six hours to get it right, I should be reporting back sometime next year!

 

[Brambles]

Isaac,

Hold your shape and keep your chin up! This is all about being logical, patient and learning about the vagaries of “the machine”.

In my view, you are pointing in the right direction - and will get there.

There will be a local expert in atmospheric burners who is much better than I am - but they are quite rare (knowledgeable atmospheric burner people) - not people who are better than me! -

From our correspondence, you seem to have a very good understanding of the principles - please continue to share your issues - we will get there in the end!

If it is any consolation, I make excellent friends with very old Aga’s (sorry not Rayburn’s) - but no profit - because they always take so much longer to resolve!! Their offspring have conventional oil or gas heating systems - so that keeps me solvent!!

 

[Isaac]

Isaac,

Hold your shape and keep your chin up! This is all about being logical, patient and learning about the vagaries of “the machine”.

In my view, you are pointing in the right direction - and will get there.

Thanks for the encouragement!

please continue to share your issues - we will get there in the end!

OK, the latest oddity. I think the inner wick isn't lighting (or not as it should anyway). When I look to check the flame colour (as I do each time I've relit it) I can only really see flames coming from the outer ring, it's not very easy to see the inner ring, so I wasn't sure, but that's what it looks like. Then today, I went to re-light it (after a flue tweak) and a strange thing happened. I accidentally got the timing wrong for letting the burner fill, I usually wait 15mins, but this time I ended up only waiting just under 10. Anyway, I dropped a match into the inner ring, nothing happened. I looked at my watch and realised my mistake, but, just for the hell of it, I dropped a match into the outer ring. It lit up with a full flame immediately.

Am I mad for thinking this all points to the possibility that my inner wick isn't lighting? Could the unburnt fumes be coming from there, could that be what the 'explosions' were early on (it suddenly catching)? Is it even possible for the inner ring to remain unlit when the one just outside of it is on high flame? On the one hand it sounds like it would explain the symptoms, but on the other is sound just implausible on the face of it? I mean, for a start oil has to travel through the inner ring to get to the outer one, right?

 

[Brambles]

Isaac, that is not unusual on vaporising burners - the inner wick will light when the burner door is closed and the combustion air is being drawn.

You are correct, the oil flows to the inner burner first.

 

[Isaac]

Isaac, that is not unusual on vaporising burners - the inner wick will light when the burner door is closed and the combustion air is being drawn.

You are correct, the oil flows to the inner burner first.

Ok, thanks. So not that then. My logic being...

You're saying if there's oil in the inner ring, the wick will light eventually presuming there's enough air flow.

So in my case...

There has to be oil in the inner ring because there to be oil in the outer ring (and in order for me to forward it as a reason for the fumey smell). There has to be enough air flow because my outer ring flame is blue. Therefore my wick must be alight (it has both oil and air flow), I just can't see the flame properly for whatever reason. Does that sound right?

I'm taking it out again today and I'm going to really get all the seating of rings and chamber lid as flush as I can, tweak the restrictor plate a bit, and see what happens.

 

[Brambles]

Your interpretation with the burner rings is correct. When the burner door is open, you do not get the see the same burner flame picture as it is in use with the door closed.

You can test this if you wish by marking the inner wick - then putting the range into operation.

 

[Isaac]

Your interpretation with the burner rings is correct. When the burner door is open, you do not get the see the same burner flame picture as it is in use with the door closed.

You can test this if you wish by marking the inner wick - then putting the range into operation.

OK - the Rayburn's been fine (almost) for the last couple of days. I took the restrictor plate out and realised (I think) it had a particular 'way round'. a way it has never been (I rent this place), but a way which is obvious once it's but like that, it fits the flue outlet perfectly, which it never did.

Anyway, I put the restrictor plate back the right way round, but the smell persisted. then I closed the bottom chamber door properly and the smell went away, has been like that for days now.

So - to explain the bottom door (the one where the burner sits (where I presume the ash pan used to be when it was solid fuel) - One of the engineers I had out when I first moved in told me that these rayburn conversions need a lot of air and to leave the bottom door open a crack to help supply them. I've always done so and it's never been a problem, but then the restrictor plate's never been on right either.

So, is it possible that the restrictor plate and the air inlet have to be kind of 'matched' to get the air flow right? That fixing the restritcor plate was the right thing to do, but it needed the air inlet to be fixed too to match it? Or have I just made myself another problem by not giving the flame enough air? I'm really reluctant to touch the whole set-up now as it seems to be working fine.

 

[Brambles]

Well done!!

In essence, the starting point is to ensure that the draw in the flue is sufficient (-1mm H2O) if you have the ability to measure it - that will ensure that products if combustion are drawn away and that combustion air is pulled.

As long as the room the range is in is adequately ventilated you will always have sufficient combustion air to feed the burner.

The burner door should never be left open - it should also be adequately sealed. The range draws combustion air from the low level vents up to the burners. If the door is open, this flow is interrupted, but far worse is the danger of any blow back from the burner - the burner door is there to protect you and the kitchen in the unlikely event of that happening.


The above us also why it is difficult to assess the flame picture, because when the door is open the burner is not in its steady state. In an ideal world the burner door would have an inspection window.

So for improving the air flow, you modify the restrictor plate - to do this, make a second restrictor plate - a copy of the first in thin sheet steel and make slight modifications to see the impact. Once you are happy with it, copy the mods to the original restrictor plate.

You are trying to get a draw that gives you a dull red surface to the burner with a blue flame ( no yellow) immediately above it. Too much draw and the flame will start to lift off the burner.

In reality on an old stove, it will always be a compromise - but it looks like you have already achieved that - and now have a good knowledge of the idiosyncrasies of the range.

Personally, I would not use the engineer again who suggested leaving the burner door slightly open. Normally after conversion from wood (or solid fuel) to oil, you want less not more combustion air.

If it is any consolation, I am really struggling at the moment to get an Aga that I have converted from oil to biomass chips to perform reliably. A nightmare!!