| Document type | Operation Guide |
|---|---|
| Document number | 160.54-O2 |
| Equipment | YK Centrifugal Chiller |
| Brand | YORK |
| Revised | 2025-04-25 |
| File size | 1.3 MB |
Fault codes in this document
1 of these messages are explained on a page of their own — cause, what to check, reset — written from this manual:
Table 1 – Operation analysis chart
| Code / display | Meaning | Cause | Action | Page |
|---|---|---|---|---|
| Abnormally high discharge pressure | Temperature difference between condensing temperature and water off condenser higher than normal. | Air in condenser. | 23 | |
| Abnormally high discharge pressure | High discharge pressure. | Condenser tubes dirty or scaled | Clean condenser tubes. Check water conditioning. | 23 |
| Abnormally high discharge pressure | High condenser water temperature. | Reduce condenser water inlet temperature. (Check cooling tower and water circulation.) | 23 | |
| Abnormally low suction pressure | Temperature difference between leaving chilled water and refrigerant in evaporator greater than normal with high discharge temperature. | Insufficient charge of refrigerant in evaporator | Check for leaks and charge refrigerant into system. | 23 |
| Abnormally low suction pressure | Temperature difference between leaving chilled water and refrigerant in evaporator greater than normal with high discharge temperature. | Variable orifice problem. | Remove obstruction. | 23 |
| Abnormally low suction pressure | Temperature difference between leaving chilled water and refrigerant in the evaporator greater than normal with normal discharge temperature. | Evaporator tubes dirty or restricted. | Clean evaporator tubes. | 23 |
| Abnormally low suction pressure | Temperature of chilled water too low with low motor amperes. | Insufficient load for system capacity. | Check prerotation vane motor operation and setting of low water temperature cutout. | 23 |
| High evaporator pressure | High chilled water temperature. | Prerotation vanes fail to open. | Check the prerotation vane motor positioning circuit. | 23 |
| High evaporator pressure | System overload. | Be sure the vanes are wide open (without overloading the motor) until the load decreases. | 23 | |
| No oil pressure when the SYSTEM START button is pressed | Low oil pressure displayed on control center; compressor does not start. | Oil pump running in wrong direction. | Check rotation of oil pump (Electrical Connections). | 23 |
| No oil pressure when the SYSTEM START button is pressed | Low oil pressure displayed on control center; compressor does not start. | Oil pump not running. | Troubleshoot electrical problem with oil pump VSD. | 23 |
| Unusually high oil pressure develops when the oil pump runs | Unusually high oil pressure is displayed when the oil pressure display key is pressed when the oil pump is running. | High oil pressure transducer defective. | Replace low or high oil pressure transducer. | 24 |
| Oil pump vibrates or is too noisy | Oil pump vibrates or is extremely noisy with some oil pressure when pressing OIL PRESSURE display key. | Oil not reaching pump suction inlet in sufficient quantity. | Check oil level. | 24 |
| Oil pump vibrates or is too noisy | When the oil pump is run without an oil supply it vibrates and becomes extremely noisy. | Worn or failed oil pump. | Repair/Replace oil pump. | 24 |
| Reduced oil pump capacity | Oil pump pumping capacity. | Excessive end clearance pump. | Inspect and replace worn parts. | 24 |
| Reduced oil pump capacity | Oil pump pumping capacity. | Other worn pump parts. | Inspect and replace worn parts. | 24 |
| Reduced oil pump capacity | Oil pump pumping capacity. | Partially blocked oil supply inlet. | Check oil inlet for blockage. | 24 |
| Oil pressure gradually decreases (Noted by Observation of Daily Log Sheets) | When oil pump VSD frequency increases to 55 + hz to maintain target oil pressure. | Oil filter is dirty. | Change oil filter. | 24 |
| Oil pressure system ceases to return an oil or refrigerant sample | Oil refrigerant return not functioning. | Filter-drier in oil return system dirty. | Replace old filter-drier with new. | 24 |
| Oil pressure system ceases to return an oil or refrigerant sample | Jet or orifice of oil return jet clogged. | Remove jet, inspect for dirt. Remove dirt using solvent and replace. | 24 | |
| Oil pump fails to deliver oil pressure | No oil pressure registers when pressing OIL PRESSURE display key when oil pump runs. | Faulty oil pressure transducer | Replace oil pressure transducer. | 24 |
| Oil pump fails to deliver oil pressure | No oil pressure registers when pressing OIL PRESSURE display key when oil pump runs. | Faulty wiring/connectors. | 24 |
Every row above cites the page of this document it came from, and each one is re-read against that page by an automatic check before publication. The short table of all YORK YK messages: fault codes.
Manufacturer document, published here as reference material for equipment we supply. The original lives at docs.johnsoncontrols.com. The rights holder may ask us to take it down — we will.