lou-in-usa
Member
- Joined
- Mar 13, 2018
- Messages
- 23
- Reaction score
- 11
I thought it might be helpful to put together a brief troubleshooting guide for folks who find themselves with an oil burner not starting, at the most inconvenient time, like a holiday weekend when your local service company gets a premium for an "emergency" service call.
So my experience is with the Beckett AFG model burner, but the principles might apply to other burners. Let me say from the outset, if you aren't mechanically inclined and have no experience with mechanical systems, you should not be experimenting, and you should call a qualified oil burner service company, one reason is safety, and the other is that you could easily make things worse, especially if you think you "fixed" the problem, and you never have a qualified technician inspect your burner.
I have found that most failures are a cascade of events and problems that combined, caused an all-out failure, and you may find and "fix" one problem that gets your burner working again, but that may not be the ultimate reason for the failure that you found.
So here is a list in order of likelihood of failure, that I have found:
These all presume your thermostat is working and calling for heat, and you haven't run out of oil, or have an air-lock in a supply line because you ran low on oil.
1. The electrodes (18) of the igniter are degraded and worn away so much that the igniter spark will no longer jump the gap reliably.
2. Oil nozzle (19) is clogged and not spraying a fine pattern. (Nozzle is missing from picture, but screws into the brass fitting shown on the end of the nozzle tube.)
3. High voltage spark transformer(13) is internally broken and no longer generates the voltage needed to jump the gap on the electrodes. (Many times this happens because of mal-adjusted/worn-out electrodes and the transformer constantly having to output more voltage because the spark gap is too wide on the electrodes.
4. The motor to pump coupling shaft (8). (This is a plastic shaft that connects the shaft of the motor, between the squirl-cage fan and the oil pump. The "D" slot in the shaft can round-out over time and doesn't turn the pump shaft reliably after that.)
5. The flame sensor (17) "cat-eye" might need to be cleaned or is broken and needs replacement.
6. The flame retention head (20) has deteriorated and is blocking the oil spray pattern or the air swirl pattern.
7. High pressure solenoid valve is broken. (Test coil continuity with a VOM; test voltage to the "valve cordset" (4) with the AC setting on a VOM)
8. Internal oil pump screen is clogged, or the pump (5) is worn out. (You must have new gasket if you take the pump apart.)
This list is by no means all that can go wrong, but if your burner is tripping-out then it's likely due to one of more of the items above. An annual inspection, cleaning, and maintenance of your burner is the best way to make sure it doesn't give you any problems during the heating season, and the best way to make sure you aren't wasting money with poorly adjusted air flow, fuel pressure and delivery, and so on.
Every other year the burner should be pulled out of the furnace so the combustion chamber insulation in the furnace can be inspected. Among other problems a maladjusted burner can create, it can also deteriorate the furnace combustion chamber insulation to the point where it is no longer protecting the combustion chamber metal, and you are burning a hole in it and it will eventually fail. This happened to me after a maladjusted burner kept flooding the mineral insulation with oil on every burner start-up, and eventually the burner was firing directly against the metal of the heat exchanger, and over time, burned a hole in it. This is an example of one maladjustment leading to other failures. I keep a few things on hand these days because they are inexpensive, and eventually I need them for maintenance since they are regular service items:
1. Shaft Coupling (8)
2. Electrodes (18) and the adjustment gauge for adjusting electrode gap (18) and nozzle (19) depth behind the combustion head (20).
3. Flame sensor Cad Cell (17)
4. Nozzle (Not shown. Buy the same flow-rate and spray angle and pattern you currently have, or that is recommended by the furnace manufacturer; it's stamped on the nozzle.)
5. Fuel line filter. (Not shown)
Some last notes, if you've run out of fuel, you will have to bleed the air out of your line(s) and pump using the "Air Bleed" as pictured in the diagram. You do this by connecting a clear flexible tube to the line and run it into a bottle until you don't see air bubbles in the fuel. Remember to close valves on supply line(s) before cracking them open, this will limit your oil loss, and keep air from filing the entire line with air. Only work on the furnace if you have a fire extinguisher designed for oil fires, nearby; and do not do any work around an open flame, especially if your burner has flooded the inside of the furnace or the surrounding area, with oil. Just call a technician. Have trays to capture oil that leaks when you crack open supply lines, and kitty litter on hand to soak-up spills. Use the appropriate wrenches, nut-drivers and screw drivers for each fastener, Channel-Lock pliers are not a substitute for wrenches and drivers.
So my experience is with the Beckett AFG model burner, but the principles might apply to other burners. Let me say from the outset, if you aren't mechanically inclined and have no experience with mechanical systems, you should not be experimenting, and you should call a qualified oil burner service company, one reason is safety, and the other is that you could easily make things worse, especially if you think you "fixed" the problem, and you never have a qualified technician inspect your burner.
I have found that most failures are a cascade of events and problems that combined, caused an all-out failure, and you may find and "fix" one problem that gets your burner working again, but that may not be the ultimate reason for the failure that you found.
So here is a list in order of likelihood of failure, that I have found:
These all presume your thermostat is working and calling for heat, and you haven't run out of oil, or have an air-lock in a supply line because you ran low on oil.
1. The electrodes (18) of the igniter are degraded and worn away so much that the igniter spark will no longer jump the gap reliably.
2. Oil nozzle (19) is clogged and not spraying a fine pattern. (Nozzle is missing from picture, but screws into the brass fitting shown on the end of the nozzle tube.)
3. High voltage spark transformer(13) is internally broken and no longer generates the voltage needed to jump the gap on the electrodes. (Many times this happens because of mal-adjusted/worn-out electrodes and the transformer constantly having to output more voltage because the spark gap is too wide on the electrodes.
4. The motor to pump coupling shaft (8). (This is a plastic shaft that connects the shaft of the motor, between the squirl-cage fan and the oil pump. The "D" slot in the shaft can round-out over time and doesn't turn the pump shaft reliably after that.)
5. The flame sensor (17) "cat-eye" might need to be cleaned or is broken and needs replacement.
6. The flame retention head (20) has deteriorated and is blocking the oil spray pattern or the air swirl pattern.
7. High pressure solenoid valve is broken. (Test coil continuity with a VOM; test voltage to the "valve cordset" (4) with the AC setting on a VOM)
8. Internal oil pump screen is clogged, or the pump (5) is worn out. (You must have new gasket if you take the pump apart.)
This list is by no means all that can go wrong, but if your burner is tripping-out then it's likely due to one of more of the items above. An annual inspection, cleaning, and maintenance of your burner is the best way to make sure it doesn't give you any problems during the heating season, and the best way to make sure you aren't wasting money with poorly adjusted air flow, fuel pressure and delivery, and so on.
Every other year the burner should be pulled out of the furnace so the combustion chamber insulation in the furnace can be inspected. Among other problems a maladjusted burner can create, it can also deteriorate the furnace combustion chamber insulation to the point where it is no longer protecting the combustion chamber metal, and you are burning a hole in it and it will eventually fail. This happened to me after a maladjusted burner kept flooding the mineral insulation with oil on every burner start-up, and eventually the burner was firing directly against the metal of the heat exchanger, and over time, burned a hole in it. This is an example of one maladjustment leading to other failures. I keep a few things on hand these days because they are inexpensive, and eventually I need them for maintenance since they are regular service items:
1. Shaft Coupling (8)
2. Electrodes (18) and the adjustment gauge for adjusting electrode gap (18) and nozzle (19) depth behind the combustion head (20).
3. Flame sensor Cad Cell (17)
4. Nozzle (Not shown. Buy the same flow-rate and spray angle and pattern you currently have, or that is recommended by the furnace manufacturer; it's stamped on the nozzle.)
5. Fuel line filter. (Not shown)
Some last notes, if you've run out of fuel, you will have to bleed the air out of your line(s) and pump using the "Air Bleed" as pictured in the diagram. You do this by connecting a clear flexible tube to the line and run it into a bottle until you don't see air bubbles in the fuel. Remember to close valves on supply line(s) before cracking them open, this will limit your oil loss, and keep air from filing the entire line with air. Only work on the furnace if you have a fire extinguisher designed for oil fires, nearby; and do not do any work around an open flame, especially if your burner has flooded the inside of the furnace or the surrounding area, with oil. Just call a technician. Have trays to capture oil that leaks when you crack open supply lines, and kitty litter on hand to soak-up spills. Use the appropriate wrenches, nut-drivers and screw drivers for each fastener, Channel-Lock pliers are not a substitute for wrenches and drivers.
