I have an Ultra 2 bunn slush machine. One hopper

There are several possibilities that could be causing your problem. However, the most common fault is the solenoid coils which open the valve to allow refrigerant into each hopper. Please see the ports manual at "http://www.partsguru.com/user/Bunn Manual ULTRA2 Illustrated parts 32081.0001.pdf". I think the part you will need is "32133.0001". Before you get carried away though there is one simple thing you can do to prove it is the solenoid coil. In a two-bowl machine there are two solenoids. These are identical. Swap them over and the fault should follow the valve. Here is a site with some useful information about how to do this.http://sites.google.com/site/sencotelsol... There are several possibilities that could be causing your problem. However, the most common fault is the solenoid coils which open the valve to allow refrigerant into each hopper. Please see the ports manual at "http://www.partsguru.com/user/Bunn Manual ULTRA2 Illustrated parts 32081.0001.pdf". I think the part you will need is "32133.0001". Before you get carried away though there is one simple thing you can do to prove it is the solenoid coil. In a two-bowl machine there are two solenoids. These are identical. Swap them over and the fault should follow the valve. Here is a site with some useful information about how to do this. http://sites.google.com/site/sencotelsolenoid/home