5. SERVICING UNIT
TROUBLE SHOOTING GUIDE |
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PROBLEM | POSSIBLE CAUSE | SUGGESTED SOLUTION | |||
1. | 1a. No power to heater | a. | Cycle the Power Switch off then on. | ||
| does not operate. |
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| disconnect. | |
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| proper ground. | |
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| applicable. | |
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| 1b. Defective transformer | b. | Check secondary voltage. | |
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| If no 24 volts, replace transformer. | |
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2. | Pump/Blower NOT running. | 2a. Loose wire(s) | 2a. | Check wiring connection(s) | |
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| does not draw | |
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| move and inspect impeller. | |
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| 2b. Defective pump | 2b. | Replace cartridge or entire pump as | |
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| needed. | |
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| 2c. Defective blower. | 2c. | Clean and inspect blower wheel. | |
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3. | Unit energized, pump and | 3a. Limit control (operating limit) | 3a. | If Red LED on circuit board is ON, | |
| blower running, but burner is | or sensor may be defective. |
| check for a loose sensor connection | |
| NOT on. |
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| or defective sensor. Sensor resis- | |
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| tance readings: | |
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| 60°F = 45,500± 2300 ohms | |
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| 80°F = 28,000± 1300 ohms | |
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| If Yellow LED is ON , water tempera- | |
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| ture is above set point. When either | |
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| Red or Yellow LED is ON, heater will | |
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| be shut down. Check 24V, power at | |
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| OUT and COMM terminals. If no 24V | |
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| is present when Red or Yellow LED is | |
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| not ON, replace control board. | |
3b. Blocked vent or defective air vent switch.
3b. Excessive vent length or resistance or blocked vent will open the air vent switch. Remove blockage. If switch stays open, replace air vent switch.
3c. Tripped or defective manual | 3c. Depress the Manual Reset High Limit |
reset limit. | switch. |
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| 185°F or less. |
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| (High Limit trips may be due to a |
| damaged pump). |
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| Procedure. |
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| High Limit |
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