Servicing the oil furnace
The oil furnace must be serviced annually. The reason for this is oil is a liquid. Unlike gaseous fuels, the liquid must be turned into a gas before it can be burned. This requires a nozzle that can atomize the oil and with the addition of heat, turns it into a gas so it can be burned.
Oil fed to the nozzle must be very clean. So the first part of the annual service is replace the oil filter. Between the oil tank and the filter, there will be a valve. This valve will be a little different than most valves but it operates in the same way. Turn clockwise to close and counter clockwise to open. The valve is a fire safety valve that shuts off when overheated. When this valve is turned off to service the filter, a light tap on the stem with a small tool will make sure it has seated closed. Before disassembling the canister, place several layers of newspaper on the floor beneath the canister. Also a coffee can should be placed under the canister to catch the oil. The General brand filter canister seems to be the most common filter used although a spin on throw away is a better option. If the filter has been replaced annually, it can probably be reused with a new filter element. The one shown in the video below had not been serviced regularly so the canister should be replaced. Remember, the oil must be clean or the nozzle will plug. The canister can be cleaned by using laundry detergent and water. Once the canister has been cleaned and inspected, a new element can be installed. The new element comes with a new gasket for the canister. Once the canister has been reassembled, the valve can be turned on. There will be one or 2 bleed ports on the canister. The bleed port farthest from the oil valve is the only one necessary to use. Open the oil valve. If any leaks are noted, immediately shut off the valve. The bleed valve is just a small bolt that communicates with the outflow of oil. Loosen the bolt. Do not remove it. You will see air bubbles as the air is displaced. The there is a smooth flow of oil out of the port, tighten the bolt with a new gasket. Wipe off all oil from the canister. Run your finger around the seams to check for leaks. Remove the coffee can. Do not remove the newspapers until you are ready to leave the job. They are you final check for leaks. Any oil on the newspapers mean a leak. The video below shows how this is done.
Oil fed to the nozzle must be very clean. So the first part of the annual service is replace the oil filter. Between the oil tank and the filter, there will be a valve. This valve will be a little different than most valves but it operates in the same way. Turn clockwise to close and counter clockwise to open. The valve is a fire safety valve that shuts off when overheated. When this valve is turned off to service the filter, a light tap on the stem with a small tool will make sure it has seated closed. Before disassembling the canister, place several layers of newspaper on the floor beneath the canister. Also a coffee can should be placed under the canister to catch the oil. The General brand filter canister seems to be the most common filter used although a spin on throw away is a better option. If the filter has been replaced annually, it can probably be reused with a new filter element. The one shown in the video below had not been serviced regularly so the canister should be replaced. Remember, the oil must be clean or the nozzle will plug. The canister can be cleaned by using laundry detergent and water. Once the canister has been cleaned and inspected, a new element can be installed. The new element comes with a new gasket for the canister. Once the canister has been reassembled, the valve can be turned on. There will be one or 2 bleed ports on the canister. The bleed port farthest from the oil valve is the only one necessary to use. Open the oil valve. If any leaks are noted, immediately shut off the valve. The bleed valve is just a small bolt that communicates with the outflow of oil. Loosen the bolt. Do not remove it. You will see air bubbles as the air is displaced. The there is a smooth flow of oil out of the port, tighten the bolt with a new gasket. Wipe off all oil from the canister. Run your finger around the seams to check for leaks. Remove the coffee can. Do not remove the newspapers until you are ready to leave the job. They are you final check for leaks. Any oil on the newspapers mean a leak. The video below shows how this is done.
Now we move up to the burner assembly. There will be a motor on one side of the burner, a pump on the opposite side and in the center top, will be a spark transformer. Above the motor will be a cad cell relay which is the flame safety control. I am using a Beckett burner in this illustration, so some parts will be in other positions with other brands. All brands must have the same parts. You will not be able to see the gun assembly and nozzle until they are removed. The transformer is usually hinged at the back and with the removal of 2 screws at the front, an can be opened. This will give access to the gun assembly. The gun line is a small diameter tube running from the pump to the gun line. Removing the gun line (be sure to loosen both ends of the gun line for easier removal) will give access to the gun assembly. The gun assembly can then be removed for service. The gun assembly can then be disassembled for cleaning. Once disassembled, the parts should be thoroughly cleaned and flushed with detergent and very hot water. The electrodes have ceramic insulators that should be inspected for cracks. They can be wet sanded to get them clean. The nozzle should be removed so it can be replaced.
At this point you need to flush out the gun with oil from the system. This will flush through any contaminants you may have introduced into the system. Reinstall the gun assembly to the gun line outside the burner with the gun pointed toward a coffee can. Start the unit. Oil will flow out the gun line until the cad cell safety shuts down the burner. You have done 2 things here. You have flushed the system and you have checked the cad cell safety for proper operation.
Next, a new nozzle should be installed. Never remove a nozzle and reinstall it. If it has been installed and used, it must be replaced. Placing the nozzle into the gun assembly must be done carefully to keep it clean. In the video below I have demonstrated how all this is done.
At this point you need to flush out the gun with oil from the system. This will flush through any contaminants you may have introduced into the system. Reinstall the gun assembly to the gun line outside the burner with the gun pointed toward a coffee can. Start the unit. Oil will flow out the gun line until the cad cell safety shuts down the burner. You have done 2 things here. You have flushed the system and you have checked the cad cell safety for proper operation.
Next, a new nozzle should be installed. Never remove a nozzle and reinstall it. If it has been installed and used, it must be replaced. Placing the nozzle into the gun assembly must be done carefully to keep it clean. In the video below I have demonstrated how all this is done.
Again, we must keep everything as clean as we can. With the top open, we can see the burner fan. It should be rotated to be sure it is not binding up. This is not really simple to do because there is normal resistance to rotation from the pump. There should be some resistance but it should be easy to rotate. While you are there, you should check the blower wheel for dirt. If it is dirty, the motor should be removed. The wheel will come with it.
Next, the gun should be set up. When you took the gun assembly apart for cleaning, the electrodes were removed and need to be reset. In the video below I am using a tool designed for setting the electrode position. If not tool is available, The electrodes should be just forward of the end of the nozzle, about 1/16". Be careful not to have the electrodes too far forward as they can short to the burner head. The end of the electrodes should be about 7/16" above the centerline of the nozzle. The gap between the electrodes should 1/8". Once this is done, the gun assembly can be replaced in the burner. There is a threaded and knurled nut that holds the gun in place. One caution about this nut is to make sure the flat side of the nut is toward the burner housing. The video shows how this is done. The gun line can then be reinstalled. On this type of burner, the end of the gun should be 1, 1/8" behind the end of the burner. You will not be able to see this with the burner installed. I would not change the adjustment of the burner depth unless there is a problem with the flame. Once the gun is installed and tightened down, you need to clean the transformer terminals and check the cad cell. The cad cell is located between the transformer terminals. Remove and clean its surface. Some of the burners have oilers on the pump motor that need to be oiled.
Once this is done, the burner air will have to be adjusted. On this type of burner, there are 2 air adjustments. The mass air adjustment on the circumference is seldom used for residential burners. The adjustment near the pump will be the one you will make most adjustments on. We are not adjusting the air at this time, that will be done in a later video. As always, the video below gives some demonstrations.
Next, the gun should be set up. When you took the gun assembly apart for cleaning, the electrodes were removed and need to be reset. In the video below I am using a tool designed for setting the electrode position. If not tool is available, The electrodes should be just forward of the end of the nozzle, about 1/16". Be careful not to have the electrodes too far forward as they can short to the burner head. The end of the electrodes should be about 7/16" above the centerline of the nozzle. The gap between the electrodes should 1/8". Once this is done, the gun assembly can be replaced in the burner. There is a threaded and knurled nut that holds the gun in place. One caution about this nut is to make sure the flat side of the nut is toward the burner housing. The video shows how this is done. The gun line can then be reinstalled. On this type of burner, the end of the gun should be 1, 1/8" behind the end of the burner. You will not be able to see this with the burner installed. I would not change the adjustment of the burner depth unless there is a problem with the flame. Once the gun is installed and tightened down, you need to clean the transformer terminals and check the cad cell. The cad cell is located between the transformer terminals. Remove and clean its surface. Some of the burners have oilers on the pump motor that need to be oiled.
Once this is done, the burner air will have to be adjusted. On this type of burner, there are 2 air adjustments. The mass air adjustment on the circumference is seldom used for residential burners. The adjustment near the pump will be the one you will make most adjustments on. We are not adjusting the air at this time, that will be done in a later video. As always, the video below gives some demonstrations.