Air in Oil - Can the pump be bad?

Is your next logical step to replace the pump? What's your definition of "logic"?

It worked right up until you walked in the room, so we can assume its due to something you touched. (A little logic + deduction.)

What model Beckett, and what nozzle? The only thing you did on the oil side is replace the nozzle? No filter? No pump strainer? If no, then that would rule out a suction leak. That was before you replaced the TL and braided lines, though. Now who knows?

Did you adjust the electrodes? Are they set correctly? Is the head on the assembly or fixed on the air tube? What's it look like? Shine a flash down the air tube? Coke around the perimeter? Is asking for an ohm reading on the eye too much?

If the only thing you touched was the nozzle, its possible you've got a faulty nozzle. I had one last week. First time since I can't remember when. A .65 80°B Delavan. Not likely, but possible.

There's a "find a contractor" link at the top of the page. Click it. But stop trying to service an oil burner if you don't have the tools. You don't need logic as much as you need the tools at this point. I can't ask what I really want to ask because you don't have the tools to provide the answers.

I would look at the tiger loop. Having one is supposed to eliminate the air in the fuel. Where is your filter? Did the tech disconnect the TL and get the lines back on wrong. If the lines are plumbed correctly, try bypassing the TL and see if the problem goes away. Could be some crap in the TL that escaped in the maintenance service. I think you will find that it is a restriction in the fuel supply not the burner pump.

Some other thoughts, check the fuel flow at the in port on the TL. If the tank is full there should be a flow of fuel due to gravity. You have cavitation in the burner pump resulting in vapor bobbles.

When did you change the TL?, Did it run ok after the change. Did you change both?

Runs fine until ignition drops out? That's the hint! What are combustion readings? What type of primary control?

@NJeffro said, “The strainer was replaced last season and was squeaky clean.”

How do you know the strainer is squeaky clean? Did you remove the strainer cover and inspect the strainer? If you did, that is the first place I would look for a vacuum leak that might let air into the oil line system with a Tigerloop.

I carried a full box of pump gaskets for the Clean Cut, A2, and B2 fuel pumps, and I would always change the gasket. I also carried some of the O-rings for the Riello pumps. They could be reused over and over again, but they might eventually fail. You can't get the burner to operate if there is a compromised O-ring on the strainer cover.

The fact that you need to bleed the pump with a Tigerloop tells me you don't understand how they work. You do not need to bleed a fuel pump equipped with a Tigerloop. If you do, then there is an air leak that is greater than the small leaks the Tigerloop will hide, allowing the burner to operate even when there is a small air leak. I think that Tigerloop is the best thing since the bypass plug was introduced.

After you make sure the fuel pump gasket is not the problem, then a vacuum gauge will help you find the source of the air leak. Do you own a 0 - 30 vacuum gauge

the oil is foamy

There IS a vacuum leak!

I think you're looking at this all wrong.

He is getting FOAM=AIR. Of course, if you are getting air the burner may stay lit when ignition is on and fail when ignition goes off. That is completely normal.

Solve the foam-air problem and the burner will be fixed. Shut the oil off at the tank and disconnect the oil line. Fill a bucket of oil and connect a short line to the burner and run the burner out of the bucket. See what happens.

Maybe a bad TL. Flares don't usually go bad but anything is possible.

That is why I dislike overhead single pipe systems.

In the old day whenever you had lift you would use a 2 pipe system which is what I would use and eliminate the TL.

But I am in the minority on that and will get trashed for even suggesting it. Bring it on.

If you replace the fuel pump, then anything that is wrong with the pump will be eliminated.

• If it is the pump seal, then the problem is gone
• If there is a bad pressure adjustment piston, then the problem is gone
• If there is a bad pump cutoff, then the problem is gone
• If there is a defective solenoid, then the problem is gone
• If it has a bad $$1.77 gasket on the strainer cover, then the problem is gone.
• If it is missing the $2.40 bypass plug, then the problem won't go away unless you remember to install the bypass plug.

All you need to do is spend about $130.00 wholesale for a new Fuel pump PF20322U and any of the lower cost problems will go away. I just look at this statement "This year after cleaning the boiler and installing a new nozzle, it fires right up and runs fine until the ignition turns off." and ask myself what was included in the "cleaning the boiler". then I look at this statement "The strainer was replaced last season and was squeaky clean." and wonder how @NJeffro knows the strainer is squeaky clean without removing the strainer cover. Then i think It worked fine before you touched it and it does not work now. I believe that is not a coincidence. The heater cleaning included something in the fuel system that has changed.

Then I read my tagline below: “After you make that expensive repair and you still have the same problem, what will you check next?” Substitute the word fuel pump for expensive and see if you can look at the fuel pump gasket before you purchase a fuel pump.

You already did this: “After you make that TigerLoop repair and you still have the same problem, what will you check next?” The next thing I would check is whether or not the $2.40 bypass plug was properly set when the TigerLoop was commissioned.

This sounds like a gravity feed from the tank to the burner that worked fine without the TigerLoop operating properly, since there was no bypass plug for years before this problem. It may not be a fuel pump at all, but rather a loss of the gravity feed as a result of a new air leak at the high point in the fuel line from the tank to the fuel pump. This could happen during a maintenance visit and after you spend several hundred dollars on the expensive parts like a pump and a tiger loop, you then come back and read this comment and look at the less expensive repairs .

If the bypass plug was installed in the fuel pump that the air would show up in the TigetLoop bowl. since there is no foam in the bowl, then the gasket or the bypass plug or both are where an oil-burner man with 45 years experience might look first before swapping parts.

I'm pretty much @EBEBRATT-Ed on this one. And I share his dislike of overhead lines. However, let's go back to square one here.

Is this an overhead line? I assume so, since there is a Tiger Loop.

Is the oil level in the tank above the pump inlet to the burner? If it is, the first step is the integrity of the entire line of pipe. Disconnect the oil line at the pump and prime it and, while it is primed (gets messy — got hand soap? Pig mat? cap it tightly. Let it sit for 24 hours. Now uncap it (hopefully ou will need to have it over a bucket…). If you don't get a good solid flow, you have a vacuum leak somewhere along that line.

If the pump inlet is above the oil level in the tank, the principle is the same: remove the line from the pump and prime it (you'll need a vacuum pump). Put a sensitive vacuum gauge on the line and cap it (maintaining the prime) and note the reading. Again, let it sit for 24 hours — if the vacuum reduces (the absolute pressure rises) you have a vacuum leak somewhere.

If you do find you have a leak, finding it is the next problem. And yes, flares can fail. Particularly if they have been undone and that made up again. And remember that a vacuum leak may or may not — often not — show up under a pressure test!

Also remember that with rare exceptions gaskets and o-rings should not be reused. Even if they look just fine, replace them when you reassemble.

IDK what the problem is because I am not there.

But if your getting foam when you bleed the pump you have an oil supply issue.

This is probably the 3rd or 4th time I have posted that.

If it was me I would pressure test everything

Those GENERAL filter have a few places they can leak. The bolt that comes up from the bottom of the cannister. The rubber gasket where you change the filter and the little screws on top have gaskets as well.

Its probably going to be something simple and stupid when you find it.

My first guess would be filters or Tiger loop. Then flares. make sure if you have any Firomatic valves they are wide open. The stem should be showing above the valve wheel. They are a left hand thread

After you make that expensive repair and you still have the same problem, what will you check next?

This is something I said to the mechanics who worked for me over and over again.

I remember one of my mechanics asking me to purchase a new $500 wholesale blower motor for a high-velocity air handler because he didn't think the existing motor looked like the correct one. Two days later, when the manufacturer sent us the motor, it looked identical to the one already in the air handler.

He then determined that the refrigerant charge was the problem. The system had too much refrigerant. By recovering about 8 ounces of refrigerant, the system worked great, and I was left with a $500 special-order motor that I was never able to sell to anyone. It's only money, right? to quote a very smart repair man (sarcasticly stated).

• Is there a valve at the tank? If not them maybe you should put one there.
• Place a plug or cap at the end of the suction line in the tank. You can do this with a temporary fitting. You can remove the suction line from the bottom of the tank for this test.
• Then attach a vacuum gauge on the line at some location between the tank end of the suction line and the fuel pump.
• Operate the pump in order to get the vacuum up to 10" vacuum.
• The fuel line will hold the vacuum if there are no air leaks.

If there is a leak the vacuum will drop. Find a point mid-way between the fuel pump and the tank end of the capped off fuel line. Re-test and see if the vacuum leak goes away. Continue to test at some different point until you find a test that proves leak free. There are 16 different locations on this diagram that I constructed from your description

They are indicated by a red X on the diagram. Zoom in on the illustration to see all the red "x"s. Some of those fittings have more than one place where air can leak in under a vacuum.

Start in the middle and move closer to the pump if you find a leak, until you find no leak. If you don't find a leak, move farther from the pump until you do find one. This will help you locate the source of the air leak.

Hope this helps.

I've been following and not commenting since I don't know what's going on, but I do have a question and then a comment. OP mentioned several times that there's no sign of air/bubbles/foam in the TL. I have NEVER seen a TL ever, so I confess that I don't know how they work, but my question is that -

- if there is NO sign of air in the TL dome, does that not eliminate everything that precedes the TL, such as filter housing leaks, flares, and piping from the TL back to the tank? If that's not universally true, then that suggests to me that OP should begin to check from the tank to the TL, whereas he's been concentrating from the TL to the pump. But if the TL is running clear, that means his problem is between the pump and TL, yes?

My comment is his CAD cell resistance. I realize he's running a low volume nozzle, but 1600-1800 ohms seems dangerously close to lock-out. For instance, I'm running a 0.75@100lb W nozzle and I'm getting about 250 ohms on an AFG.

Take the OSV out and try running the burner without it. The OSV may be defective and pulling air in. Worth a try. The OSV needs a vacuum to open. You can always put it back in if it is not the issue.

Try bleeding the pump with a clear hose that fits tight to the bleeder, and have the other end immersed into a can with oil in it (which is btw, the way the manufactures want you to bleed it). Only turn it a 1/4 turn.
You could be pulling air in thru the bleeder.