Oil fired Rayburn persistent fumes after service.

[Isaac]

I've been servicing my own oil fired Rayburn for years without any problems. Immediately after my last service, a few days ago, it smelt really fumey, stank the whole house out. It also would have regular (what I call mini-explosions - it's not that dramatic, but I can't think of a better word, a bit like suddenly going from low flame to full flame for a second). I thought that oil vapour leak would be the cause of both issues (thought maybe I'd put something back too loose), so I had the burner out again, made sure the chamber lid and rings were flat on, checked for oil leaks, put everything back.

That solved the mini-explosion problem entirely. I now have a smooth, entirely blue flame without so much as a splutter. But the fume problem is still there, even possibly a bit worse.

Fume smell is the same on low or high setting (so I'm presuming oil levels can't be a problem (not that I didn't check the levels anyway). The smell is coming from the door as much as the hotplate, so It can't be seals (there's no seal on this model's door).

All the usual culprits of fumey smells I've read about seem to be to do with the rayburn needing a service, not a consequence of it getting one. Other culprits such a chimney blockages, fuel filter clogging etc., I can't see any way they could have just suddenly come about as a consequence of a service. The day before the service it was fine.

Any clues as to where to look next would be much appreciated.

 

[oz-plumber]

If you're not qualified to work on the boiler, the best advice you're going to get is switch it off and find someone who is qualified to work on it.
The fumes you smell may be a sign that there a dangerous fumes that you can't smell inside your house.....eg CO

 

[ShaunCorbs]

@Best any help ? ?

 

[Isaac]

If you're not qualified to work on the boiler, the best advice you're going to get is switch it off and find someone who is qualified to work on it.
The fumes you smell may be a sign that there a dangerous fumes that you can't smell inside your house...eg CO

Well, I've since had two qualified engineers in and neither has managed to fix the problem and I'm now nearly £200 less well of as a result, so that didn't help much I'm afraid.

I've got three CO detectors in the house, all of which I've brought down to the kitchen where the Rayburn is, none of which have gone off in the intervening days, so if CO is a problem then the various detector manufacturers have a lot to answer for.

Short of just throwing money at qualified engineers (both of whom basically just carried out exactly the same service procedure I do every six months), has anyone else got any ideas?

 

[Stigster]

Seeing the engineers you got in must surely(?) have used their gas analysers to "sniff" around the door and any other seals where combustion products are conveyed, the problem must lie elsewhere. Any leak of combustion products are very easy to detect given the sensitive nature of gas analysers so I would have expected them to find any leaks.

What their analysers will not detect is the smell of evaporating unburned oil. When removing and replacing the burner during your service, it is possible to disturb the flexible oil supply/return hoses and cause a small weep of oil and it doesn't take much to make a stink. Even if you have checked the tightness of the burner hoses, I would take some blue paper towel (it shows even tiny spots of liquid present) and wipe around every oil line joint around the burner. There are several as I'm sure you are aware so methodically go over every one with the paper and see if you can find any weeps.

If that fails to find the problem then I'm sorry, I'm stumped but it's worth a try. Best of luck!

 

[Chalked]

Here’s what you need to do.
Start with removing the burner. Then the combustion chamber top. Then the baffles, or turbulators ( which ever your boiler comes with)
Clean out the chamber.
Check for damages baffles and heat absorption pad at the back.
Replace burner nozzle.
Check electrodes.
Replace oil supply flexi pipe.
Clean oil filters.
Reinstall burner, fire up and ch check burner pressure .
Install your flue gas analyser probe and set co2 to manufactures settings. Check co content.

Now I expect you haven’t got a fga. So please call an engineer who will do the above.
You will save in the long run and the boiler will be more reliable.
Your 2 engineers are rubbish. Where abouts are you? Any oil guy would have no problem sorting your boiler.
Most problems like yours are caused by leaking oil pipework, or flue seals. All, can be detected

 

[Best]

Could you put some photos of burner on here?

 

[Brambles]

Chalked has a pretty comprehensive list to guide you to the solution. All I would (could) add is are you sure that the burner has not been cracked during your service ? (It is very easy to do, (crack it, not check it). Check and recheck that the oil supply line to the burner is not weeping oil.

If you have the equipment to undertake an oil rate combustion test, that will probably give you a few pointers as to where the problem lies.

On a final point whilst your focus on monitoring CO is admirable, don’t ignore the risks of unburnt oil fumes in a domestic environment.

 

[Isaac]

What their analysers will not detect is the smell of evaporating unburned oil. When removing and replacing the burner during your service, it is possible to disturb the flexible oil supply/return hoses and cause a small weep of oil and it doesn't take much to make a stink. Even if you have checked the tightness of the burner hoses, I would take some blue paper towel (it shows even tiny spots of liquid present) and wipe around every oil line joint around the burner. There are several as I'm sure you are aware so methodically go over every one with the paper and see if you can find any weeps.

If that fails to find the problem then I'm sorry, I'm stumped but it's worth a try. Best of luck!

Thanks for this. I've tried but couldn't find any moisture. I think it's got to be what you say though as nothing else makes sense so I will keep trying to track down where the oil is coming from.

On a final point whilst your focus on monitoring CO is admirable, don’t ignore the risks of unburnt oil fumes in a domestic environment.

The WHO says that Kerosine fumes are safe. The HPA compendium states only that "Toxicity occurs if kerosene is inhaled while being ingested (aspiration)" and "The most common health effect associated with chronic kerosene exposure is dermatitis". I checked, of course, as soon as this problem arose. Do you have some other source to the contrary?

 

[Brambles]

Two points:

I think you will find that Kerosine has traces of benzine and n-hexane in it, both of which are toxic. It is certainly an issue in the Indian sub continent where kerosene is used extensively for cooking.

In more general terms, you should not operate any appliance or engine where it is suspected that the fuel supply is not properly contained or leaking.

Most people would not drive a car with an obvious smell of unburnt fuel.

 

[SimonG]

Are we talking pressure jet or vapourising appliance here?

 

[Brambles]

They are atmospheric or pressure jet depending on the model.

 

[Best]

Are we talking pressure jet or vapourising appliance here?

That was what I have been trying to find out, but still wondering

 

[SimonG]

They are atmospheric or pressure jet depending on the model.

Yes, aware of that, but a little bit vague from op. If its vapourising then I wont comment as have very little experience. Now if its pressure jet I'll be all over it like jam on toast.

 

[Isaac]

Are we talking pressure jet or vapourising appliance here?

Vapourising (unfortunately, given your area of expertise).
[automerge]1570688570[/automerge]
Just had the whole lot out again, re-fitted everything, changed wicks etc. Still the same smell. Seeing as there's some ambiguity I'll just clarify a few points.

It's a vapourising oil burner - two channels and a central chamber with a lid, wicks in the rings, large perforated rings sitting between the wicks. all this in a converted 1969 Rayburn Royale.

Most importantly (which seems to have been missed by a couple of respondents) the smell was completely absent the day before the service, then arrived (badly) the day I re-lit it. It's been serviced to a greater or lesser extent (we've tried different things each time) six times since. The smell got slightly better the first time, then it's stayed the same since. So without any further explanation as to why...

It's not the flue - how could the flue suddenly become blocked coincidentally on the same day I happened to be servicing it? (not only that, but I've tested it with lit newspaper and it draws fine)

It's not the seals - I could have put things back wrong once, but all six further occasions with two of them not even me doing it, especially when no such thing has happened on the previous 12 times I've serviced it. Again, if the seals are at fault it would have to be an astonishing coincidence.

It's not oil the levels - the adjusters on both the oil control valve and the burner are completely rusted, the relative levels are exactly the same as they've been (probably for the last 20 years!). I've also checked and timed the oil supply rate.

It's not the wicks - I've changed them to no effect.

It's not the oil itself - Same as the others, it was fine the day before the service, bad after. Same oil.

It's not the rings or the chamber lid - I've checked both are seated completely flush and down to bare metal where they meet. Also, again, the same procedure I've done twelves times in the past and now got wrong six times times in a row, doesn't make sense.

It's not leaking oil anywhere - I've had paper towels down, as advised, around the whole burner unit and pipework for nearly an hour with it full (but unlit). Not a drop of oil anywhere but inside the burner itself.

The only thing that I noticed during this last test, it that the oil kind of wicked outside of the chamber and channels of it's own accord. Just like if you made a cup out of paper, oil would sort of wick up the sides beyond the fill level. That's what the oil was doing, it was like the burner was made of paper (rather than cast iron) and the oil was sort of 'seeping' through it. Just a little bit so that the i could see a damp mark on the outer edge. I don't know if this is normal, however, nor do I have the faintest idea what might cause it that would tie in with the fact that this happened after a service.

I'd be really grateful for any ideas, but please don't just suggest I get an engineer in. I may well do so, but there are a finite number of things that can go wrong, with a finite number of causes. If none of the experts here can even suggest something that might actually cause this problem (given the history I've outlined above) then why would an engineer who comes to see it suddenly be able to think of something? I just need some ideas, even if I just pass them on to an expert I employ to fix them for me.

 

[Gasmk1]

becasue sometimes the trained and experienced eye will see things that the untrained dont. there is obviously a problem and if its fumes you need to get an oil engineer in

 

[Brambles]

Without teaching you to such eggs, as I guess you already know this:

I am not too familiar with Rayburns, but am very familiar vaporising Aga’s.

The burner must be perfectly level, the drip rate correct and the inlet totally clear of carbon deposits ( without widening or damaging the jet). Sometimes an ultra sound cleaning is needed

The flame pattern on high should be even and totally blue, - when on low, the burner top should glow dull red.

In your earlier post you referred to “the burner” popping - that is oil starvation - how did you correct that if the adjuster valves are rusted? - or have I miss understood.

Normally by taking time and thoroughly cleaning and methodically rebuilding the burner they work. Occasionally you get a burner that is level after setting up, heats unevenly and then distorts to being off level in use - that can cause poor combustion.

Are you sure that you have not cracked the cast iron part of the burner?

What I do with two older (1970’s) ranges that I service (and are difficult / problematic to set up) is have a second burner set. So at service time, I clean the chamber and swop over the burners. I then refurb and clean the old burner in a workshop environment ready for the next service.

Sadly, with old ranges, they all have their own idiosyncrasies

 

[Isaac]

becasue sometimes the trained and experienced eye will see things that the untrained dont. there is obviously a problem and if its fumes you need to get an oil engineer in

I'm not at all suggesting I wouldn't get an expert in. It's just that I've wasted money on two already. What I'm asking here is what could it be (what are all the options), not how I could identify which of the options it is. If no-one can even think of anything it reasonably could be then I'm reluctant to pay for an expert to just come round and confirm that he too doesn't know what the problem is. So far I've been able to rule out the options that people have suggested just by logic alone, unless I'm going to accept massive coincidence as part of the explanation (which at this rate I might have to, but not without a thorough investigation).

The burner must be perfectly level, the drip rate correct and the inlet totally clear of carbon deposits ( without widening or damaging the jet). Sometimes an ultra sound cleaning is needed

OK, I think I've done that, obviously my cleaning could be improved, but it's never been a problem before, so probably not this one.

The flame pattern on high should be even and totally blue, - when on low, the burner top should glow dull red.

Yep, flames totally blue, burner glowing red.

In your earlier post you referred to “the burner” popping - that is oil starvation - how did you correct that if the adjuster valves are rusted? - or have I miss understood.

Weird thing that. I took the burner out, scraped really well at the chamber lid, which still had a little carbon on it, made sure everything was really well seated, put it all back and no more popping. I can only presume that the small amount of carbon was enough, or maybe I'd not seated everything properly. Certainly odd, and I'm sure it's connected somehow, but it's not popped again since my first re-service.

Normally by taking time and thoroughly cleaning and methodically rebuilding the burner they work. Occasionally you get a burner that is level after setting up, heats unevenly and then distorts to being off level in use - that can cause poor combustion.

Interesting - would it go back to level again when cold? I've checked levels each time I've had the burner out and they've been OK each time. By OK I mean just like they always have been.

Are you sure that you have not cracked the cast iron part of the burner?

Can't be sure, but the seepage is not limited to one place, it's around the chamber lid and at the very top edge of the channels all around, so not like I would expect a crack to show.

What I do with two older (1970’s) ranges that I service (and are difficult / problematic to set up) is have a second burner set. So at service time, I clean the chamber and swop over the burners. I then refurb and clean the old burner in a workshop environment ready for the next service.

Good Idea. One of the solutions I'm thinking I might do is just buy a new burner and keep the old one a s a spare. Can I still buy burners, and do I need to worry about what size pipe it's connecting to, or are they all standard?

Sadly, with old ranges, they all have their own idiosyncrasies

So I'm finding. I just read on some other forum someone who had this smell for four years, despite servicing twice a year, they changed engineers and after the first service by the new engineer the smell went away. Apparently the engineer couldn't even say what he'd done!

 

[Brambles]

Issac,

Do you you think there is any possibility that you have inadvertently disturbed the flue closure plate?

If you are getting a good blue flame picture, I would expect any minor seepage of oil at the burner to be drawn either for combustion or unburnt up into the flue. If the flue seal has been disturbed that may account for your smell.

 

[Chalked]

Vapourising (unfortunately, given your area of expertise).
[automerge]1570688570[/automerge]
Just had the whole lot out again, re-fitted everything, changed wicks etc. Still the same smell. Seeing as there's some ambiguity I'll just clarify a few points.

It's a vapourising oil burner - two channels and a central chamber with a lid, wicks in the rings, large perforated rings sitting between the wicks. all this in a converted 1969 Rayburn Royale.

Most importantly (which seems to have been missed by a couple of respondents) the smell was completely absent the day before the service, then arrived (badly) the day I re-lit it. It's been serviced to a greater or lesser extent (we've tried different things each time) six times since. The smell got slightly better the first time, then it's stayed the same since. So without any further explanation as to why...

It's not the flue - how could the flue suddenly become blocked coincidentally on the same day I happened to be servicing it? (not only that, but I've tested it with lit newspaper and it draws fine)

It's not the seals - I could have put things back wrong once, but all six further occasions with two of them not even me doing it, especially when no such thing has happened on the previous 12 times I've serviced it. Again, if the seals are at fault it would have to be an astonishing coincidence.

It's not oil the levels - the adjusters on both the oil control valve and the burner are completely rusted, the relative levels are exactly the same as they've been (probably for the last 20 years!). I've also checked and timed the oil supply rate.

It's not the wicks - I've changed them to no effect.

It's not the oil itself - Same as the others, it was fine the day before the service, bad after. Same oil.

It's not the rings or the chamber lid - I've checked both are seated completely flush and down to bare metal where they meet. Also, again, the same procedure I've done twelves times in the past and now got wrong six times times in a row, doesn't make sense.

It's not leaking oil anywhere - I've had paper towels down, as advised, around the whole burner unit and pipework for nearly an hour with it full (but unlit). Not a drop of oil anywhere but inside the burner itself.

The only thing that I noticed during this last test, it that the oil kind of wicked outside of the chamber and channels of it's own accord. Just like if you made a cup out of paper, oil would sort of wick up the sides beyond the fill level. That's what the oil was doing, it was like the burner was made of paper (rather than cast iron) and the oil was sort of 'seeping' through it. Just a little bit so that the i could see a damp mark on the outer edge. I don't know if this is normal, however, nor do I have the faintest idea what might cause it that would tie in with the fact that this happened after a service.

I'd be really grateful for any ideas, but please don't just suggest I get an engineer in. I may well do so, but there are a finite number of things that can go wrong, with a finite number of causes. If none of the experts here can even suggest something that might actually cause this problem (given the history I've outlined above) then why would an engineer who comes to see it suddenly be able to think of something? I just need some ideas, even if I just pass them on to an expert I employ to fix them for me.

Sorry i presumed it was a pressure jet burner . I’m 54 an d haven’t done many vaporising burners.
these are tricky to set up and are done with mostly the naked eye. And a second sense of flame picture.
i would advise you get an older engineer to come and service your boiler .ask them if they have good experience in vaporising burners. apart from aga’s they can’t be many left!

 

[Isaac]

Do you you think there is any possibility that you have inadvertently disturbed the flue closure plate?

Yes, It's not impossible, however...

The problem has inexplicably been fixed. After my last take-everything-out-and-put-it-back-again the smell persisted for about half a day, i turned the dial up a fraction (just to get our hot water back) and the smell went away, 24hrs later it's still gone. I should say, in the previous couple of weeks wrestling with this problem I have tried all sorts of settings so it's not just a matter of higher flame=no smell, it must additionally be something I did last time.

Anyway, I haven't dared try it on any other settings yet (I just want a break from fixing it for a while), but there's one matter I'd like to ask your opinion on, if it's OK. All this recent fixing issue has made me hyper-attentive to flame colour and now I'm not trusting my memory of what it's normally like. I've had 100% blue, but sometimes I look and there's a trace of yellow/orange, just at the tip of the otherwise blue flames. I'll try to get a photo, but it looks just like this image from the guidance I've been using.

not literally 100% blue. Is that something I need to get checked out, or is that part of what you'd still call 'blue flame'?

 

[Brambles]

Issac,

The flame should be completely blue. The yellow flicker is sign of incomplete combustion - which could just be dirt in the burner.

I would source a second burner set and next time you service the range swop out the burners and give the existing ones a thorough clean and check for cracks and / or porosity in the cast iron.

Having said all the above - the yellow flicker you have at the moment is not a major issue - but it will increase the volume of carbon deposit / sooting.

It may settle down after a few days.

Good luck

 

[Isaac]

Issac,

The flame should be completely blue. The yellow flicker is sign of incomplete combustion - which could just be dirt in the burner.

I would source a second burner set and next time you service the range swop out the burners and give the existing ones a thorough clean and check for cracks and / or porosity in the cast iron.

Having said all the above - the yellow flicker you have at the moment is not a major issue - but it will increase the volume of carbon deposit / sooting.

It may settle down after a few days.

Good luck

Thanks.

Unfortunately the smell has just come back again. I haven't done anything except open the top door (I was thinking of getting a photo of the flames), literally haven't touched anything - how's that even possible?

The only thing I can think of was that it was really windy the 24hrs over which there was no smell. So maybe all that was happening was the smell was being drawn up the flue better (as I think you've mentioned should happen). I suppose that might indicate something wrong with the flue (so I've booked to have it swept anyway - just in case), but I think it unlikely because I can't see how it would suddenly become a problem overnight. If you remember, this problem was non-existent the day before the service and the arrived the day after. Can a flue block up that quickly?

One weird thing I'd like to ask an expert. In our flue box, the exit from the Rayburn itself is blocked by two sheets of metal with a 1-2cm slot cut in one of them - meaning the entire exit hole is narrowed to about 1x5cm. It's always been like this and I presumed it was something to do with the conversion to oil (the Royale is a solid fuel range really). The reason I ask is that if 1x5cm is the correct exit hole, then it's very hard to see how any flue blockage could possibly result in a draw less than that (the flue is about 10cm diameter), but if it's not normal, then I suppose all sorts of things might have gone wrong with it? Why might the flue exit need to be narrowed in the first place?

 

[Brambles]

Issac,

Starting with the restrictor plate in the flue. This is normally a plate that slides across the bottom of the flue inlet to optimise the “pull” from the flue on the boiler. The pull on the flue ( if you can measure it ) for a vaporising burner should be less than -1 mm H2O but not more than -1.5mm H2O. The plate you describe has probably been custom made to give those conditions rather than adjusting the restrictor plate. That is not unusual - it is a one time setting normally.

I assume that when you had the “engineers” out they measured the boiler draught? You cannot do that yourself - unless you have the equipment!
What you can do is:

For the flue, check for spillage using a match test all around the spigot, joints and restrictor (if fitted).

Check all the door seals on the range - thay must all be tight fitting and not pass air in either direction.

Check that the room ventilation providing the combustion air is properly sized for the boiler. The boiler should run properly with all doors and windows closed any extract fans switched off, so that all combustion air is only coming through the permanent vents.

Also may be worth rechecking that the burner shells are all undamaged and seated properly - they should be a tight fit into the burner to be as airtight as possible.

Apologies, I have no real immediate advice - I think that you now just need to work through the complete basic set up of the range to ensure that it is all correctly configured. I appreciate that you probably do not need it, but the starting point is always a flue clean

 

[Isaac]

Starting with the restrictor plate in the flue. This is normally a plate that slides across the bottom of the flue inlet to optimise the “pull” from the flue on the boiler. The pull on the flue ( if you can measure it ) for a vaporising burner should be less than -1 mm H2O but not more than -1.5mm H2O. The plate you describe has probably been custom made to give those conditions rather than adjusting the restrictor plate. That is not unusual - it is a one time setting normally.

Thanks. I've had that plate out, cleaned it and put it back several times during services as I always check the flue box as part of my service. I've never been particularly accurate in how I put it back (not to the mm type accuracy) so it's in basically the same place it's always been. One less potential cause I think.

I assume that when you had the “engineers” out they measured the boiler draught? You cannot do that yourself - unless you have the equipment!

I wasn't in the room with them all the time, but I don't think they did anything like that. They didn't mention it anyway. They just took the burner out, scraped it a bit, put fresh wicks in (I think), vacuumed around the chamber and fluebox and that was that. As far as I know. I clearly need to get myself some more technical engineers.

For the flue, check for spillage using a match test all around the spigot, joints and restrictor (if fitted).

Done. Match was steady all around, good draw in through the air inlet. There's no sign of any actual draught, even from the hob and chamber door where the smell is coming from.

Check all the door seals on the range - thay must all be tight fitting and not pass air in either direction.

The hob seal is new(ish), the burner chamber door doesn't have a seal and never has had. There's not even a place for one to go as far as I can tell.

Also may be worth rechecking that the burner shells are all undamaged and seated properly - they should be a tight fit into the burner to be as airtight as possible.

Done. Measured them with a flat-plate. They're completely flat at the base. The engineer mentioned possibly using exhaust sealant paste if the problem continued, but I'm reluctant to do that as it's obviously never needed it in the past.

Apologies, I have no real immediate advice - I think that you now just need to work through the complete basic set up of the range to ensure that it is all correctly configured. I appreciate that you probably do not need it, but the starting point is always a flue clean

Not at all, you've been really helpful, I greatly appreciate it. The flue clean is booked in (over a month off though, our sweep is very popular at this time of year), so I'll just have to wait for that and go from there.

Thanks again for your help.

 

[Brambles]

Thanks,

Very helpful responses.

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.

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.

 

[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?