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PICTURE 4: HEAD AND AIR ADJUSTMENT
HeadAir
To access the head and air adjustment, remove the plastic cover from the rear of the housing, using the supplied 4 mm allen key. The left dial is the head adjustment dial; the right dial is the air adjustment dial. These dials can spin 360o 22 times for the head and 32 times for the air. Using the same 4 mm allen key, turn the numbered dials to the appropriate head setting (please refer to Chart 5 on page 8). These recommended settings are only approximate settings. Actual field conditions will vary and require a certified technician to adjust the burner. OEM settings may differ.
When to adjust the Air
The air shutter is a mechanical shutter. Do NOT over crank the air shutter. General rule: if the CO2 (Carbon Dioxide) is too low, then close the air shutter. If the CO2 is too high, then open the air shutter. Note: Do NOT set the CO2 higher than 9.8% for Natural Gas or 11.5% for LP Gas. If the CO (Carbon Monoxide) is above 100 ppm, there is either too much air or too little air.
Check the CO2 level and adjust the burner.
When to adjust the Head
The retention head is 1/8” inside the tube when the marking reads ‘22’. There is a full ½” movement for the retention disk to move backward (to increase secondary air) or forwards (to decrease secondary air). NOTE: the head physically moves within the blast tube. Do not over crank the head dial. This movement can also be used to compensate for backpressure in the combustion area, up to 0.3” W.C.
Caution: If this is the case, the flange and the combustion chamber should be completely
sealed. This pressure firing decreases as the firing rate increases. See Graph 1. Note: the burner should be adjusted while it is firing.
Graph 1: Chamber Pressure versus Firing Rate (BTU)
| 0.35 |
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| 0.30 |
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| 0.25 |
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of Water | 0.20 |
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Inches | 0.15 |
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| 0.10 |
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| 0.05 |
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| 0.00 |
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| 50,000 | 100,000 | 150,000 | 200,000 | 250,000 | 300,000 |
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| BTU's |
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