TROUBLE SHOOTING THE GAS CONTROL SYSTEM
SIT 820 MILLIVOLT VALVE
Note: Before trouble shooting the gas control system, be sure external gas shut off is in the "On" position.
WARNING: BEFORE DOING ANY GAS CONTROL SERVICE WORK, REMOVE GLASS FRONT.
| SYMPTOM |
| POSSIBLE CAUSES |
| CORRECTIVE ACTION |
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1. | Spark ignitor will not light |
| A. Defective or misaligned |
| Using a match, light pilot. If pilot lights, turn off pilot and | |
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| electrode at pilot. |
| push the red button again. If pilot will not light - check gap | |
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| at electrode and | |
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| B. Defective ignitor (Push Button) |
| Push Piezo Ignitor Button. Check for spark at electrode and | |
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| pilot. If no spark to pilot, and electrode wire is properly | |
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| connected, replace ignitor. | |
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2. Pilot will not stay lit after |
| A. Defective pilot generator |
| 1. Check pilot flame. Must impinge on thermocouple/ | ||
| carefully following lighting |
| (thermocouple), remote wall |
| thermopile. Note: this pilot burner assembly utilizes both | |
| instructions. |
| switch. |
| a thermocouple and a thermopile. The thermocouple | |
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| operates the main valve operation (On and Off). Clean | |
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| and or adjust pilot for maximum flame impingement on | |
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| thermopile and thermocouple. | |
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| B. Defective automatic valve |
| Turn valve knob to "Pilot". Maintain flow to pilot; millivolt | |
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| operator. |
| meter should read greater than 10 mV. If the reading is | |
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| okay and the pilot does not stay on, replace the gas | |
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| valve. Note: An interrupter block (not supplied) must be | |
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| used to conduct this test. | |
3. Pilot burning, no gas to |
| A. Wall switch or wires |
| Check wall switch and wires for proper connections. Jumper | ||
| burner, Valve knob "ON", |
| defective. |
| wire across terminals at wall switch, if burner comes on, | |
| Wall Switch "ON". |
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| replace defective wall switch. If okay, jumper wires across | |
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| wall switch wires at valve, if burner comes on, wires are | |
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| faulty or connections are bad. | |
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| B. Thermopile may not be |
| 1. Be sure wire connections from thermopile at gas valve | |
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| generating sufficient |
| terminals are tight and thermopile is fully inserted into pilot | |
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| millivoltage. |
| bracket. | |
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| 2. One of the wall switch wires may be grounded. Remove | |
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| wall switch wires from valve terminals if pilot now stays lit, | |
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| trace wall switch wiring for ground. May be grounded to | |
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| appliance or gas supply. | |
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| 3. Check thermopile with millivolt meter. Take reading at | |
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| thermopile terminals of gas valve. Should read 325 milli- | |
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| volts minimum while holding valve knob depressed in | |
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| pilot position and wall switch "Off". Replace faulty | |
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| thermopile if reading is below specified minimum. | |
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| C. Plugged burner orifice. |
| Check burner orifices for debris and remove. | |
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| D. Defective automatic valve |
| Turn valve knob to "On", place wall switch to "On" millivolt | |
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| operator. |
| meter should read greater than 100 mV. If the reading is | |
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| okay and the burner does not come on, replace the gas | |
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| valve. | |
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4. | Frequent pilot outage |
| A. Pilot flame may be too low |
| Clean and/or adjust pilot flame for maximum flame | |
| problem. |
| or blowing (high) causing the |
| impingement on thermopile and thermocouple. | |
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| pilot safety to drop out. |
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| B. Possible leak in liner or seals. |
| Check the venting for leaks or blockage. | |
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10003929 | 13 |