• Shutdown due to low flow/ice block: Blow dry air at no more than 5 L/min through the flow path of the cold head, and replace the line dryer (the line dryer is probably saturated). If the ice block continues, make sure there are no leaky connectors and replace the diaphragm in the pump if needed. A good indication of a leaky connector is the heat percent. The coldstream should run with a stable heat percent between 10 % - 20 %, a lower heat percent is probably due to a leaky connector.
• Coldstream cannot reach programmed temperature but is stable: The coldhead may have lost vacuum.
• Condensation/ice on coldhead SUCT connector: An inward leak in the SUCT path may have thrown off the heat exchange in the coldhead.
• Icing on nozzle : Wrong flow of dry air, should be between 10 to 15 L/min, or dry air compressor need to be serviced.
• Shutdown due to large temperature error: Ice in the small dewar is formed on the vent port. When the auto fill is attempting to fill the dewar, warm gas cannot escape causing the coldstream fault.
• Oxford Cryostream 600 Manual
• Oxford Cryostream 700 Manual

---

Protein Crystallography Web Master