The filter that fits into the bottom of the unit keeps floating up. Basically the did not design it tight enought to fit. So now you have a boiling hot cup of water and your trying to manipulate the filter back in with spoons. No fun. I emailed them and they suggested preheating it with hot water. The filter then expand and stays. I don't want to have to add steps to compensate for their design/manufacturing mistakes.I now wedge it in tightly with a strip of tea bag (bought the roll your own tea bag assortment) That works, but again. Shouldn't happen.There is a competing product with a large, wide bowl. I would try that one instead. Another advantage, the wider bowl will allow you to load the filter more easily. I have a large hand and its hard to fit it into ingenuitieas narrow cup.On a positive note their tempored clear glass teapot is great. Tea stays Hot for 20+ minutes.