Ummm. Not wanting to buck the trend here, but my parents have a normal fire place & chimney, which in ~25 years has been cleaned about twice... I think some people here have been in CH too long...
How long you can safely go between cleanings will depend alot on what you burn. My grandparents had a chimney fire once when they burned normal coal, not to be recommended especially as they were charged by the fire brigade for the call out since it could have been prevented if they had had their chimney cleaned (this was not in CH though).
I know, but there is this - maybe I've already been in one fire too many. Yes my parents, grandparents, aunts and uncles all have normal fires too. And my neighbours. And lots of them don't get cleaned very often. I've seen several chimneys catch fire over the years (none ours), it happens so easily and the fire brigade are never impressed. And it ain't fun trying to locate a slow fire that's gotten in between brick walls etc from a flue or chimney, and the fire brigade have to spend ages slowly pulling out your ceilings and your neighbours roof...
Also, for those renting, there's a good chance its in your contract for an annual clean plus another as part of your 'exit' clean. The flues on these wood burny thingies is very narrow compared to a brick chimney, and they do fur up with soot quickly so better to be on the safe side I reckon.
Just get your local chimney sweep to come and clean it and tell you if all is OK. In Switzerland all woodburners have to be cleaned by law every year- and this should have been done automatically. Our local chimneysweep just send a note saying the date and approximate time.
We have a similar one but a bit bigger (7.5KW) and it is amazing how much heat it gives out. Be careful if you have small kids, the 'pierre olaire' (alpine stone cladding) gets very hot and acts a bit as a storage heater. Brilliant.
I know you were just joking with this comment, but still, I wanted to say that you should definitely NOT burn treated or coated wood like that (especially considering that most Ikea stuff is treated with formaldehyde).
Some friends of mine once tore down a wooden childrens' swingset and burnt it in their backyard and ended up getting really light-headed and nauseous from the fumes because of the chemicals that the wood had been treated with.