problem with multistack chiller

[bright]

hie guys ,i have got a problem with a multistack chilled water plant supplying three floors.when i switch it to manual , pumps are running ,but the chiller is desplaying a message"CHILLED WATER INTERLOC OPEN" , so i cant not understand this ,can someone help?

[Brian_UK]

Is there a water flow problem?

Is the water flow switch contact closed?

[adam0606]

The Flow switch on the water pump open. Chiller won't run until switch closes...

[Brian_UK]

Think we told him that seven months ago. :D