If the FOB is cleaned regularly, there should not be any performance issue other than it is not mounted plumb vertically. Normally the issue is not with the FOB but with the system set up. Switch FOB to another location and this may determine for you if it is truly the FOB. Tell us which FOB (manufacturer) you are using and specifics on the system - temperaure, gas pressure and source, etc.
Scott Zuhse, Instructor
Micro Matic Dispense Institute