Stove secondary air control - dangerous?

azzeretti

I have an 5KW insert stove for a fair few years. I got talking to a guy in a stove shop this week and the subject of the secondary air control come up. I mostly burn coal in the stove and I use that control with the 2 primary vents. I mostly get the fire going, then close the secondary and leave the primary open a half turn. I've been happy with the heat output using these settings. Anyway, this guy tells me this isn't advisible as , apart from the smoke on the glass, it can cause dangerous sooth build up in the chimney.

I don't mind the glass, being living with that for years, but does anyone know if this dangerous? Should I not be closing the secondary vent?

confusedeire

My 2nd Vent is on top I only open it on start up and close when red hot when burning coal. The only other time I open it is when burning timber but close the bottom Vent then as it's more efficient to burn the timber with the top Vent . I can't think of any danger in leaving it closed.

Sanchez83

The top air vent which is primarily a glass cleaner should not be closed fully for the reason the man in the stove shop showed you.All stoves which are Defra approved in the UK should not allow the top air vent to close fully.