Gas stove service

Hi, I have a Rangemaster with double ovens. They do not heat up enough and need adjustment. Is this easy to do or do you know who i can call to service it?
I have gone around in circles trying to get a service guy as it is not under warranty and I don't know where it was bought (came with the house)
I'm in Dublin and it is run on bottled propane.
Thanks

I believe http://www.cfquadrant.ie are distributors for Rangemasters