All I could suggest John, is take the jet out and pressurise the tank. Then just let the paraffin flush the whole system out before you replace the jet.
You might find it is debris in your paraffin, so strain it thru a couple of layers of your wifes finest nylon stockings. Best to take her out of them first.
Many times, people just prick the jet rather than removing it, and it is the same bit that keeps blocking it up.
Other than that, it's about all I can come up with. There is not much else to go wrong with them on that side of things.
John