Hello all,
Wondered if anyone could help shed some light on why my newly installed (used) Rayburn Royal mf seems to smoke excessively (from the flue top). It's a cooker only installed with a 6" twin wall flue which rises to about 4m above a flat roof. The thing that's baffling me is that I'm burning kiln dried hardwoods (which burn very cleanly in our Rojek boiler and produce no smoke once heated up) but with the spin wheel open to any degree and the flue damper open it chucks out a dark brown smoke which doesn't ease up even when everything has warmed up. I've tried all combinations of spin wheel open/shut and various damper positions but nothing calms it down. It has a very good draw and doesn't takes minutes to get going like a furnace. The only way I can stop it smoking is to close the spin wheel fully and almost fully shut the damper then it produces barely a whisp of smoke. Thing is, I don't like shutting it down within a few minutes of lighting as it's obviously going to soot up the appliance and flue. This seems almost backwards to me, as ime a woodburner would smoke more if you bank it down soon after lighting. Have checked the inside of firebox and under hot plate and nothing wrong, flue was new, wood around 18% mc. Surely it should be burning very cleanly given the above? Can too much draw make dry wood smoke excessively? I ain't never seen it with 2 woodburners and a boiler but this setup seems special. Any ideas gratefully received! Thanks Jim

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Yes, should've said it is a reconditioned Royal, new firebricks throughout. Thought initially it might have been some sort of residue from them or fire cement but still happening after half a dozen burns up to roasting temp on oven.

Does sound like wet wood. Kiln dried just means it went into a kiln but no guarantee of dryness. It's possible the Rojek being a far more modern and hopefully cleaner burning is able to cope better. Do an oven dry test on a sample of wood to see how dry it is unless you have trusty moisture meter.

Chop a piece off, weigh it stick it in the aring cbd for a month reweigh it and then calculate moisture content.

Yes

Ok thanks, will do the oven test on the joinery bits. I didn't think it'd be the wood as if it was damp, I thought it would still smoke when banked down, but will try it. My first call was to the company who recond it, they said it's the fuel, but as mentioned it burns so cleanly on other appliances I dismissed it...didn't think it'd be that fussy but as someone else said maybe the more modern appliances deal with it better. I tried some of our oak logs last night and it did seem better but still smokier than I'd expect. Think I need to use the oak logs to dry the couple ton of joinery pieces I've got in the Rayburn oven 😳. Thanks for the suggestions. Cheers