A Step-By-Step Guide To Replacing Your Fuel Oil Furnace Nozzle

Changing the nozzle on a fuel oil furnace is a complex task that requires careful consideration of several factors. The nozzle's spray pattern, angle, and size in gallons per hour (GPH) must be compatible with the specific furnace model and combustion chamber design. An incorrect nozzle can lead to improper combustion, sooty operation, and even safety hazards like a puffback explosion. It is recommended that homeowners seek the assistance of trained professionals for this task, as they have the necessary training and equipment to ensure proper installation and adjustment of the new nozzle.

Identify the type of nozzle your furnace uses

The first step to identifying the type of nozzle your furnace uses is to look up your furnace's specifications. Most common brands have a clear label of the type of extruder (which in turn almost always specifies the type of nozzle). Things to look out for are the "MK" or Mark, followed by a number. MK6, MK8 and MK10 are the common extruders in budget or open-source furnaces. If you have a Prusa Mk3S+ for example, it uses a E3D V6 Hotend and the “V6” actually tells you what nozzles fit (E3D V6 Nozzles).

If you are unable to find the specifications of your furnace, you can identify the type of nozzle by looking at the nozzle itself. The numbers on the nozzle tell you the specific rating of the nozzle, the spray pattern angle, and the spray pattern type. The letter on the nozzle indicates the spray pattern. Different manufacturers use different letters for the same patterns, so it is best to use Delavan as an example, as it is the most common nozzle manufacturer. Patterns are designated as solid (B), hollow (A), and semi-solid (W). A solid nozzle indicates the vaporized oil is distributed evenly throughout the entire spray pattern. A hollow nozzle distributes more of the oil to the outer ring of the pattern, and a semi-solid is neither.

Check the nozzle size and spray pattern

The nozzle size and spray pattern are critical to the performance of the furnace. The nozzle size determines the amount of fuel being used, and the spray pattern determines how the fuel is vaporized and burned.

The nozzle size is given in gallons per hour (GPH) and is usually rated at 100 psi. The spray pattern is given in degrees and indicates the angle at which the spray comes out of the nozzle. The smaller the angle, the narrower the spray pattern. The spray pattern is designated by a letter stamped into the nozzle. The most common patterns are solid (B), hollow (A), and semi-solid (W).

When checking the nozzle size and spray pattern, it is important to consult the manufacturer's installation manual to determine the correct spray angle and GPH for the proper firing of the oil burner. The manufacturer's specifications for the nozzle size and pattern are usually found on a sticker or data plate on the oil burner or the furnace.

It is also important to note that changing the nozzle size and spray pattern can affect the performance of the furnace. A smaller nozzle size will reduce the amount of fuel being used, while a larger nozzle size will increase it. Changing the spray pattern can affect the shape and length of the flame, which needs to match the size and shape of the combustion chamber.

• Make sure the nozzle is clean and free of debris.
• Check the nozzle for any damage, such as stripped threads or leaks.
• Ensure that the nozzle is properly secured and not cross-threaded.
• Verify that the nozzle is compatible with the oil burner and furnace model.
• Consult a professional if you are unsure about the correct nozzle size or spray pattern.

Clean, tune and adjust the oil burner

To clean, tune and adjust your oil burner, follow these steps:

Firstly, ensure that your burner is switched off and that the electrical feed to the blower is disconnected. It is also recommended that you undertake this task in spring, after the burner's last use of the year.

Next, start at the chimney and work your way towards the furnace. Clean the soot buildup from the stack by removing the bolts with a wrench and placing them on a newspaper. Remove the control sensor and set it aside, then use a wire brush with a soft rag attached to gently rub off excess soot. Wipe clean with another soft rag before replacing the control sensor and bolting the stack back into place.

Now, check the draft regulator, found on the outside of the stack, and move it back and forth to ensure that it operates freely. If it sticks, carefully wipe away any accumulated soot with a cotton-tipped swab.

Replace the oil filter. Remove the filter housing by unscrewing the unit, then carefully pull out the old filter and dispose of it according to the regulations in your community. Pry the old gaskets loose with a screwdriver and wipe the housing clean before putting a new filter and gasket on and reattaching it to the furnace.

Inspect the pump strainer by removing the bolts that hold the cover on. Gently pry the inside strainer loose and soak it in kerosene to remove deposits. If the strainer shows excess wear or damage, consider replacing it. If not, put the cleaned strainer back and replace the cover.

Clean the furnace blower using the rod attachment of your vacuum to suck out any accumulated dust.

Finally, squeeze a few drops of 10-weight motor oil on the blower motor assembly to ensure smooth movement.

It is important to note that you should not attempt to adjust or clean the burner on your furnace—this part requires professional servicing.

Check the spray angle

Checking the spray angle of a fuel oil furnace nozzle is a crucial step in ensuring the efficient and safe operation of your heating system. Here's a detailed guide on how to check and adjust the spray angle:

Step 1: Understand the Spray Angle

The spray angle of a fuel oil furnace nozzle refers to the width of the spray pattern, typically measured in degrees. Common spray angles range from 30° to 90°, with narrower angles producing a more concentrated spray and wider angles creating a broader spray pattern. The spray angle is determined by the shape and size of the combustion chamber.

Step 2: Locate the Nozzle

The fuel oil furnace nozzle is usually located inside the combustion chamber. It is the component that sprays the fuel oil into the chamber for combustion.

Step 3: Inspect the Nozzle

Remove the nozzle from the furnace and examine it closely. The spray angle should be stamped or engraved on one of the nozzle's facets. It will be a number followed by the degree symbol (°). For example, you might see "80°" indicating an 80-degree spray angle.

Step 4: Cross-Reference with Manufacturer's Specifications

Refer to the manufacturer's specifications for your particular furnace model. Locate the installation manual or a guidebook that provides the recommended spray angle for your furnace. Compare this angle with the one stamped on your nozzle. They should match or be within an acceptable range specified by the manufacturer.

Step 5: Adjust or Replace the Nozzle

If the spray angle of your nozzle does not match the manufacturer's specifications, you may need to adjust or replace the nozzle. Consult a qualified technician or refer to a guidebook for specific instructions on adjusting the spray angle. In some cases, you may need to source a new nozzle with the correct spray angle.

Step 6: Clean and Maintain the Nozzle

Regular cleaning and maintenance of the nozzle are essential. Use compressed air to blow out any debris or sludge buildup. You should also inspect the nozzle for any signs of wear and tear, such as clogging or damage to the spray orifice. Replace the nozzle if necessary.

Remember, the spray angle plays a crucial role in ensuring the proper combustion of fuel and optimal efficiency of your heating system. Always refer to the manufacturer's guidelines and seek professional assistance if you're unsure about any adjustments or replacements.

Check the burner tube length and diameter

To check the burner tube length and diameter, you can refer to the manufacturer's specifications for your specific oil burner model. These specifications will outline the recommended dimensions for the burner tube, ensuring optimal performance and safety. It is crucial not to deviate from these specifications as using a burner tube with incorrect length or diameter can lead to improper combustion, sooty operation, and even safety hazards.

The burner tube length is measured from the end of the tube to the back of the combustion chamber. This length is essential as it determines the appropriate spray angle for the oil burner nozzle. A longer combustion chamber typically requires a narrower spray angle, while a shorter combustion chamber uses a wider-angle spray pattern.

The burner tube diameter, on the other hand, affects the flow rate of oil through the tube and ultimately impacts the burner's overall performance. A larger diameter will allow more oil to flow through, resulting in a higher flame and increased heat output. Conversely, a smaller diameter will restrict the oil flow, producing a smaller flame and reducing heat output.

It is worth noting that modern high-speed oil burners require precise measurements and adjustments to ensure safe and efficient operation. Therefore, it is recommended to consult a trained service technician to assist with measuring and selecting the appropriate burner tube length and diameter for your specific oil furnace model. They will have the necessary tools and expertise to fine-tune the system, ensuring optimal performance and safety.

Frequently asked questions