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Energy Saver: Furnace, Boiler & Woodstove Combustion
(continued ...) Okay, you are firmly in the second group. Let's check flame efficiency. From here, without regard to the fossil fuel or hydrocarbon energy source the rules are similar. Flame color is an indicator of combustion efficiency. The combustion chamber is sometimes sealed behind some high temperature, high quartz content glass, sometimes with a metal shutter. Other times, the flame is gravity-burning and exposed if you look through some corrugations or stampings in the outer skin of the furnace or boiler. Whatever way, the flame is usually viewable somehow if you look for it. You may need to remove a cover, slide or rotate a shield. For fossil fuels, if you see a deep blue flame, it is likely close to maximum energy efficient. If you are seeing oranges and yellows, the fuel to air ratio is wrong and you are sending unused fuel energy up the flue.
For combustible hydrocarbon machines (wood, corn, etc.), this is much more subjective. A flame that is bright yellow-white and about 4 to 6 inches tall is usually about right. If you see a short flame or flame that is dull yellow to orange then your wood pellet air-fuel mixture is wrong. Since there is so much variation here, check your manufacturer's operating manual for factory engineering recommendations. Better yet, read the next paragraph.
How much extra money are you spending on unused fuel? It doesn't take much to pay for a professional adjustment. Adjusting the fuel-to-air ratio on all equipment is best left to an expert equipped with a flue gas analyzer. Usually for $75 to $100 USD, you can have a residential heating service firm do a full service inspection. Look for their flyers in your USPS mail. When you call, verify their service at least includes measure/adjust gas pressure, test safety system, test limit ...