Modbar Steam Pressure loss

Hey guys,
I am experiencing some issues with the modbar steam module that I use. We have had these machines for about four years now, and recently there has been major drops of temperature out of no where. I cannot figure out the cause of this pressure loss. To try and work things out I have looked for any leaks and haven’t found any. We also have multiple of these steam modules that are in a few of our cafes and it is happening at both of them.