Table 3. Evaporator Troubleshooting Chart
SYMPTOMS
POSSIBLE CAUSES
POSSIBLE CORRECTIVE STEPS
Fan(s) will not operate. | 1. Main switch open. | 1. | Close switch. | |
| 2. | Blown fuses. | 2. | Replace fuses. Check for short circuits or overload conditions. |
| 3. | Defective motor. | 3. | Replace motor. |
| 4. | Defective timer or defrost thermostat. | 4. | Replace defective component. |
| 5. | Unit in defrost cycle. | 5. | Wait for completion of cycle. |
| 6. | Coil does not get cold enough to reset thermostat. | 6. | Adjust fan delay setting of thermostat. See Defrost |
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| Thermostat Section of this bulletin. | |
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Room temperature too high. | 1. Room thermostat set too high. | 1. | Adjust thermostat. | |
| 2. | Superheat too high. | 2. | Adjust thermal expansion valve. |
| 3. | System low on refrigerant. | 3. | Add refrigerant. |
| 4. | Coil | 4. | Manually defrost coil. Check defrost controls for malfunction. |
| 5. | Unit cooler located too close to doors. | 5. | Relocate unit cooler or add strip curtain to door opening. |
| 6. | Heavy air infiltration. | 6. | Seal unwanted openings in room. |
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Ice accumulating on ceiling | 1. Defrost duration is too long. | 1. | Adjust defrost termination thermostat. | |
around evaporator and/or on | 2. Fan delay not delaying fans after defrost period. | 2. | Defective defrost thermostat or not adjusted properly. | |
fan guards venturi or blades. | 3. Defective defrost thermostat or timer. | 3. | Replace defective component. | |
| 4. | Too many defrosts. | 4. | Reduce number of defrosts. |
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Coil not clearing of frost during | 1. Coil temperature not getting above freezing point | 1. | Check heater operation. | |
defrost cycle. | during defrost. | 2. | Adjust timer for more defrost cycles. | |
| 2. | Not enough defrost cycles per day. | ||
| 3. | Defrost cycle too short. | 3. | Adjust defrost thermostat or timer for longer cycle. |
| 4. | Defective timer or defrost thermostat. | 4. | Replace defective component. |
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Ice accumulating in drain pan | 1. Defective heater. | 1. | Replace heater. | |
| 2. | Unit not pitched properly. | 2. | Check and adjust if necessary. |
| 3. | Drain line plugged. | 3. | Clean drain line. |
| 4. | Defective drain line heater. | 4. | Replace heater. |
| 5. Defective timer or thermostat. | 5. | Replace defective component. | |
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Uneven coil frosting | 1. Defective heater. | 1. | Replace heater. | |
| 2. | Located too close to door or opening. | 2. | Relocate evaporator. |
| 3. | Defrost termination set too low. | 3. | Adjust defrost termination setting higher. |
| 4. | Incorrect or missing distributor nozzle. | 4. | Add or replace nozzle with appropriately sized |
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| orif ice for conditions. |
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Replacement Parts by 
Commercial Refrigeration Parts
InterLink is your link to a complete line of dependable and certified commercial refrigeration parts, accessories and innovative electronic controls for all Heatcraft Refrigeration Products (HRP) brands - including Bohn, Larkin, Climate Control and Chandler. At InterLink, we provide our wholesalers with a comprehensive selection of product solutions and innovative technologies for the installed customer base. And every product is built to ensure the same high performance standards with which all HRP brands are built — backed by a dedicated team to serve every customer need, delivering at the best lead times in the industry.
Replacement parts should be obtained from your local InterLink wholesaler. Replacement parts, which are covered under the terms of the warranty statement on page 2 of this manual, will be reimbursed for total part cost only. The original invoice from the parts supplier must accompany all warranty claims for replacement part reimbursement. Heatcraft Refrigeration Products reserves the right to adjust the compensation amount paid on any parts submitted for warranty reimbursement when a parts supplier's original invoice is not provided with a claim. For more information, call
For more detailed information on the following topics, please visit http://heatcraftrpd.com/service/publibrary.asp
for our complete Refrigeration Systems Installation and Operation Manual
Defrost Thermostat | Refrigerant Charging Instructions |
Expansion Valves & Nozzles | System Balancing — Compressor Superheat |
Refrigerant Oils | General Sequence and Operation |
Recommended Refrigerant Piping Practices | Troubleshooting Guides |
Line Sizing Charts | Preventive Maintenance Guidelines |
Hot Gas Defrost Systems | Typical Wiring Diagrams |
Evacuation and Leak Detection |
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Since product improvement is a continuing effort, we reserve the right to make changes in specifications without notice.
The name behind the brands you trust.™ 
CLIMATE
CONTROL
Commercial Refrigeration Parts
