Why is my steamer only working intermittenly? only lasts a few seconds

Why is my steamer only working intermittenly? only lasts a few seconds

The steamer only works for a few seconds before the steam pressure goes down and I have to wait until the light goes off and it resets before I can continue. Everyone else says that they are abl to use this model for 45 minutes straight. It's taking me hours to do just one room of carpet.