Vermont Castings, Majestic Products DVRT36/39/43
Troubleshooting the Gas Control System
SIT NOVA 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 | |
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| electrode at pilot | pilot and push the red button again. If pilot will not |
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| light, check gap at electrode and pilot; it should be |
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| 1/8 in. to have a strong spark. |
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| B. Defective ignitor | Push Piezo Ignitor Button. Check for spark at |
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| (Push Button) | electrode and pilot. If no spark to pilot, and elec- |
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| trode wire is properly connected, replace ignitor. |
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2. Pilot will not stay lit after | A. Defective pilot generator | Check pilot flame. Must impinge on thermocouple/ | |
carefully following lighting | (thermocouple); remote | thermopile. NOTE: This pilot burner assembly | |
instructions. | wall switch | utilizes | |
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| The thermocouple operates the main valve |
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| operation (On and Off). Clean and/or adjust pilot |
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| for maximum flame impingement on thermopile |
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| and thermocouple. |
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| B. Defective automatic valve | Turn valve knob to “Pilot.” Maintain flow to pilot; |
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| millivolt meter should read greater than 10 mV. If |
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| the reading is okay and the pilot does not stay On, |
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| replace the gas valve. NOTE: An interrupter block |
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| (not supplied) must be used to conduct this test. |
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3. Pilot burning; no gas to | A. Wall switch or wires defective | Check wall switch and wires for proper connec- | |
main burner |
| tions. Jumper wire across terminals at wall | |
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| switch; if burner comes on, replace defective wall |
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| switch. If okay, jumper wires across wall switch |
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| wires at valve. If burner comes on, wires are faulty |
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| or connections are bad. |
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| B. Thermopile may not be | 1. Be sure wire connections from thermopile at |
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| generating sufficient | gas valve terminals are tight and thermopile is |
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| millivoltage | fully inserted into pilot bracket. |
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| 2. One of the wall switch wires may be grounded. |
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| Remove wall switch wires from valve terminals; |
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| if pilot now stays lit, trace wall switch wiring for |
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| ground. May be grounded to fireplace or gas |
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| supply. |
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| 3. Check thermopile with millivolt meter. Take |
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| reading at thermopile terminals of gas valve. |
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| Should read |
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| while holding valve knob depressed in pilot |
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| 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.” |
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| operator | Millivolt meter should read greater than 100 mV. If |
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| the reading is okay and the burner does not come |
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| On, replace the gas 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 blockage of the vent | Check the vent terminal for blockage (recycling the |
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| terminal | flue gases). |
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36 | 10002428 |
