Morso 2110 riddling gate

Hi
I'm the proud new owner of the morso 2110 and I must say it is a terrific heater.
I had a question regarding the riddling grate. The instruction manual seems to indicate that when burning solid fuels it is best to leave the riddling grate open however when burning wood it is not so clear...it indicates that you can burn with it open but optimal burn will be achieved with it closed.
I m burning australian hardwood (red gum and malee root) and I have found that i am getting a far better burn (well at least I think I am!) with the riddling grate slightly open...it seems to give me more of that secondary combustion and more heat. I have the front door air intakes virtually closed when doing this.
So my question is whether firing it like this with the riddling grate slightly open will damage the heater? Or is it perfectly fine?
I also noted that similar to the first burn I did I initially got some fumes which i believe is the paint burning off?this makes me think i am now getting the heater to the temperature and burn it is designed for?
Cheers,
Angus

Thanks for replying!
Wow that manual is really different to mine!
I have a feeling it is the primary air..? It is the lever you can pull out and push in at the bottom right hand side of the heater.
What I am now confused about is what are the two dials on the doors? Are they both secondary air intake?

By the way I made a typo ! I meant riddling grate not gate! It is adjusted by pulling the lever at the bottom right hand side of the heater

Interesting. Thanks guys for all your help. It seems the Australian model, based on my quick check of the heater and read of the manual, does not have the primary air lever. We only have the two air valves (one on each door) and the shaking grate lever at the bottom right of the heater. It does say that I can 'boost' the fire by opening the shaking grate during a burn. I will experiment around to see what gives me the optimal burn.
Angus

Ok so it turns out we do have a separate model here and that model doesnt have the primary air flow lever as described in the manual linked above.
I spoke to the distributor here in aus and opening the riddling / shaking grate is an effective way of boosting the fire but if left open for too long will reduce the efficiency of the burn thereby reducing the burn time
Learning these European heaters is certainly a bit of an art form compared to
The standard coonara convection based wood heaters I've grown up with!
Cheers
Angus