TROUBLESHOOTING THE MILLIVOLT GAS CONTROL SYSTEM
Note: Before troubleshooting the gas control system, be sure external gas shut off valve (located at gas supply inlet) is in the “ON” position.
Important: Valve system troubleshooting should only be accomplished by a qualified service technician.
| SYMPTOM | POSSIBLE CAUSES | CORRECTIVE ACTION | |
|
|
|
|
|
1. | Spark ignitor will not light | A. Defective ignitor | Check for spark at electrode and pilot; if no spark and | |
| pilot after repeated | (no spark at electrode). | electrode wire is properly connected, replace ignitor. | |
| triggering of ignitor button. |
|
| |
| B. Defective or misaligned electrode | Using a match, light pilot. If pilot lights, turn off pilot and | ||
|
|
| ||
|
|
| at pilot (spark at electrode). | trigger the ignitor button again. If pilot lights, an improper |
|
|
|
| gas mixture caused the bad lighting and a longer purge |
|
|
|
| period is recommended. If pilot will not light – check gap at |
|
|
|
| electrode and pilot - should be ¹⁄₈" to have a strong spark. If |
|
|
|
| gap measures ¹⁄₈", replace pilot (Figure 8 on page 6 ). |
|
|
|
|
|
|
|
| C. Gas supply pressure errant. | Check inlet gas pressure. It should be within the limits as |
|
|
|
| marked on the rating plate. |
|
|
|
|
|
|
|
| D. Pilot orifice plugged. | Clean or replace pilot orifice. |
|
|
|
|
|
2. | Pilot will not stay lit after | A. Defective pilot generator | Check pilot flame, it must impinge on thermogenerator | |
| carefully following the | (thermogenerator). | (Figure 8 on page 6 ). Clean and/or adjust pilot for maxi- | |
| lighting instructions. |
| mum flame impingement on thermogenerator. Ensure that | |
|
|
|
| the connection between the valve and thermogenerator are |
|
|
|
| tight and secure. |
|
|
|
|
|
3. | Pilot burning, no gas to | A. Wall switch or wires defective. | Check wall switch and wires for proper connections. Jumper | |
| burner, Valve knob “ON,” |
| wire across terminals at wall switch, if burner comes on, | |
| Wall Switch “ON.” |
| replace defective wall switch. If okay, jumper wires across | |
|
|
|
| wall switch wires at valve, if burner comes on, wires are |
|
|
|
| faulty or connections are bad. |
|
|
|
|
|
|
|
| B. Thermopile may not be generating | Check thermopile with millivolt meter. Take reading at ther- |
|
|
| sufficient millivoltage. | mopile terminals of gas valve. Should read 325 millivolts |
|
|
|
| minimum with optional wall switch “OFF.” Replace faulty |
|
|
|
| thermopile if reading is below specified minimum. |
|
|
|
|
|
|
|
| C. Plugged burner orifice. | Check burner orifice for stoppage and remove. |
|
|
|
| |
4. | Frequent pilot/burner outage | A. Pilot flame may be too low or | Clean and/or adjust pilot flame for maximum flame impinge- | |
| problem. | blowing (high) causing the pilot/ | ment on thermogenerator (Figure 8 on page 6 ). | |
|
|
| valve safety to drop out. |
|
|
|
|
|
|
14