II) Description and Operation of Dual Level Control System (continued)
B. Operation |
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Water Level | Action |
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1) Below both electrodes | 1) Both “HI” and “XL” electrode circuits open. | |
| Dual Level Control turns power on to fill | |
| valve and keeps power off to thermostat. | |
| Fill Solenoid | Thermostat |
| Valve | |
| O |
ONOFF
2)Rises to low electrode above heater coils
2)“XL” electrode circuit closes. Power to thermostat turned on. Power to fill valve remains on.
| Fill Solenoid |
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| Thermostat | |
| Valve | O |
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| |
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| ON |
| ON |
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3) Rises to high electrode | 3) “HI” | electrode | circuit | closes. | Dual Level |
| Control turns power off to fill valve and | ||||
| continues power to thermostat. |
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| Fill Solenoid |
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| Thermostat | |
| Valve | O |
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| |
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| OFF |
| ON |
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4) Falls below high electrode only | 4) “HI” electrode | circuit | opens. | “XL” circuit | |
| stays closed. After a few seconds delay, | ||||
| power to fill valve is turned on. |
| |||
| Fill Solenoid |
| Thermostat | ||
| Valve | O |
| ||
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| ON |
| ON |
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5) Falls below low electrode | 5) “XL” electrode circuit now opens. Power to | ||||
(Same as condition no. 1) | thermostat is turned off. Power to fill valve | ||||
| remains on. |
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III)Quick Service Check of Dual Level Control System:
1)All wire secure and properly connected.
2)Clean the electrodes. Lime (mineral scale)
3)Check the common (ground) connection. A little looseness or dirt can cause erratic operation.
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Page 7 | American Metal Ware Hot Water Boiler |