Chimney Sweep - How Often?

[MrsTwankey]

We had a multi fuel stove fitted a couple of years ago and I've just realised we've never had the chimney swept since. (it was swept just before installation)
How often should you have it done?

I've just looked in to this very thing as we have a coal-effect gas fire in our victorian hearth but the effect is somewhat ruined by a constant stream of muck and bullets falling down said chimney.
I have to say that we've lived here for years and have NEVER had the chimney swept!
The recommended timescale is approximately x 1 per year - but more often if you burn wood (Quarterly when in use).

at least once a year if you burn coal. They say more often for wood - depends how much tar you are generating, depends on the quality and dryness of the wood.

ignore it and you risk a chimney fire, and your insurers will probably ask when the chimney was last swept...

My Dad was a chimney sweep, still is for people with coal, 1-2 times per year.

Our household insurance states it must be swept a minimum of once a year for the policy to be valid. If the stove is only used in winter and not year round then once a year should be enough. My chimney sweep puts a recommendation on the jobsheet for when it should be done next.

Thanks for your replies.
Our lounge is always cold as it faces North and we've used it quite a lot not just in the cold months. Need to get it sorted as it sounds like a big risk.