Constant air in fuel line

chsapeak

I have a weil Mclain oil burner in my home and a few weeks ago my oil provider failed to deliver and I ran out of oil. After getting the tank re-filled I bled the line a couple times and the boiler fired up nicely. A week later I came home to find it in lock out mode. I hit the reset and it didn't attempt to fire at all, I bled the pump and it fired right up. Fast another week and its out again. This time there was no getting a prime, couldn't get oil to the bleeder so I decided to change the filter assy and grab a new pump. after installing both, nothing, still couldn't get oil to the pump at all. Checked the "drive shaft" between the squirrel cage and the pump and it was stripped. I replaced that and oil was again flowing. The boiler would run fine till it shut off and set for a while, then it looses its prime. I bleed it, see a lot of foamy fuel at first then it clears out and the boiler fires when I close the bleeder. I had a tech stop by the other day to make sure all the pressures were correct, he set the pump pressure and adjusted the air that was it. Now I sit with a boiler that looses its fuel prime constantly. Today I checked all my fittings and applied pipe dope around the fittings as well. My tank is a bottom feeder and sits in my crawl space 3' below the boiler.The line is solid copper 1/2" from tank to filter, it does not run through concrete (all exposed) I'M STUMPED!! and cold..:)

Thanks in advance, first time poster but long time lurker here..
Dale

STEVEusaPA

So you have a lift job. Either you have a vacuum leak at the filter, fittings, pump screen, pump plugs, or you're not properly bleeding the fuel unit.
You could also have a blockage at the tank that's getting pulled into the oil line, then releases when the burner shuts down.

But, you say the oil company let you run out of oil? So you had to bleed the unit, then when that didn't work, you went and changed the filter, purchased another pump, then the coupling. Then fired it up without the benefits of vacuum/pressure gauges, or a combustion analyzer.

When the tech stopped by, did he check vacuum?
I think you should let the tech fix it. If I were there I would check all the fittings, and put a vacuum gauge on the pump, then vacuum check the fuel system. If all that checked out, I would power purge it. Constantly trying to bleed a dry pump will ruin the new pump too.

chsapeak

I'm planning on calling the tech back tomorrow, just trying to get through tonights 10 degree temps. I'm on auto fuel delivery from the company, after they did deliver I bled it and it fired up and ran fine for a week. Then it quit and I changed the filer cartridge, that bought me another few days. Next time it quit I bought a complete new filter assy, pump and all new fittings all sealed with yellow PTFE tape and pipe dope on outside edges. After I found the worn driveshaft it pumped like crazy. I did simply remove the new pump from the box and take out only the inlet and outlet plugs, i did not remove the other inlet plug and tape that. Might that be the problem??

chsapeak

Another note: When the boiler fires up it will run till it gets up to temp than shut itself off, if it's super cold and the circulator is running the boiler will kick back on after a few minutes and bring itself back to 180 degrees before shutting off. It doesn't trip until it sits 15 - 20 minutes then tries unsuccessfully to fire up. Then I'm back to having to bleed the air out.

rick in Alaska

Most people I have seen bleed a fuel pump try to bleed it in to a cup. I usually do at least half a gallon. You need to bleed it until no more bubbles come out, then a little more. Then I run it for a bit and bleed some more. You should have a clean, steady stream for at least ten seconds, minimum.
I try and run it with the fuel valve at the tank shut off and run it until it stops pumping and starts building a strong vacuum, then open the valve quickly. This will pull any air through quickly and speed up the process. This is especially important with the felt filters in the housing with the dome tops on them. Old timers trick.
Also, you need to make sure the fuel pump you put on is set for the same pressure as the old one. Most pumps come pre-set for 100 psi, give or take, and most new equipment is running at 140 or more.
Also, tape is considered a no-no on fuel lines.
Rick

Steamhead

You need a better tech. Where are you located?

chsapeak

I actually went under there the day i changed the pump, i shut the tank off, removed the outflow line and placed a drain pan underneath. I then opened the valve and fuel flowed easily out. This told me nothing was blocking the gravity outflow on the bottom. I also blew the line out. This morning I went back under and put pipe dope around all the fittings. The boiler is in lock out as I type and getting ready to go back out (garage) and bleed it to get my house warm for the night. I live in NY Hunter Mountain area.

lchmb

I would start with what Rick mentioned...

EBEBRATT-Ed

I am assuming you have a one pipe system and did not install the bypass plug inside the pump when you changed it. You say the tank is 3' below the boiler in the crawl space, top of the tank?bottom of the tank? or oil level in the tank?????

What is the relationship between the burner pump and the tank oil level? that's what matters. Does the line run at floor level or overhead?

The most likely place for a leak is the oil filter.

I am an old timer and most will disagree but if it has lift and it's in my house it would be two pipe.

possible that with 1 pipe and a 1/2" line the pump is having trouble getting rid of the air especially if you have a small nozzle....not much flow

HVACNUT

> @chsapeak said:
> I have a weil Mclain oil burner in my home and a few weeks ago my oil provider failed to deliver and I ran out of oil. After getting the tank re-filled I bled the line a couple times and the boiler fired up nicely. A week later I came home to find it in lock out mode.
>> First of all, if you have an actual Weil McLain (Wayne)QB180 burner, I'm sorry in advance,
I think if is in fact an oil related problem, then I would look towards the nozzle, especially after a OOO and you replaced the fuel pump and OB coupling.
My other thought is, it ran fine for a week after the first prime and start, so its possibly a faulty igniter or cad cell, dead spot in the motor windings.
You did mention that after reset, it didn't attempt to fire. Does that mean nothing happened at all? No motor?
A pic of your burner and boiler model would be helpful.

HVACNUT

> @chsapeak said:
> The boiler is in lock out as I type and getting ready to go back out (garage) and bleed it to get my house warm for the night.
>> the (garage) part caught me. Is the garage heated? Is it possible the fuel is gelling?

chsapeak

The garage is attached and the tank is under the house both areas do not get below freezing. The unit has a Beckett burner and when I say did not try to fire is when I hit the reset or if I'm there when the temp calls for it to start after a prolonged off time and I hear the fan start but you hear there is no combustion taking place. That is until i crack the bleeder for 5 - 10 seconds, get rid of the foam then as soon as I close the bleeder if fires and runs fine. It does sound as though it has a slight surging sound. like it's not running smooth.

chsapeak

Putting dope around the outside of the fitting is not going to seal the fitting against the pull of vacuum from the pump.

The line coming out of my tank is copper pipe that is flared should I unthread that and put sealant on those threads as well? I put it on the outside where the nut and pipe meet, kinda crude but figured it wouldn't be able to suck that in.

HVACNUT

Ok, at this point I would say call a different service company than was originally there. Needs a vacuum test on the oil line and a full system check/maintenance with a printed combustion analysis report.

chsapeak

HVACNUT said:

Ok, at this point I would say call a different service company than was originally there. Needs a vacuum test on the oil line and a full system check/maintenance with a printed combustion analysis report.

I agree.. I like fixing things myself but this seams to be more than just a simple fix. I'd like to call the company out that got me to sign up for their "auto delivery" program. You'll never worry about running out of our fuel. This all started after they failed at their promise that I'd never run out. Why am I stuck paying for their negligence? Their service guy that changed my nozzle (1.0 70B, the eye, adjusted my fuel pressure and adjusted the air (behind the pump) he never checked vacuum nor did he take any exhaust readings.

lchmb

pricing is not allowed here..with that said I would discuss it with the service manager...explain the run out, explain the problems that started...give them the chance to take care of it..

rick in Alaska

Like I said; If you bled the pump for 5-10 seconds, you did not bleed the pump. 30 seconds minimum until it is clear, close bleeder, re-open bleeder for a second or two, and do this until you don't get any more air out. Zero air!
My guess is if you do this, it will keep working.
Rick

chsapeak

Last night I did as you say Rick, I couldn't fit my big oil pan underneath but was able to use a cutout jug and drain close to a half gallon out. The first round I simply let it bleed out till the unit shut off (45 seconds) Closed it immediately and then second run about 30 seconds at which time it appeared pretty clear. As expected it didn't fire back up overnight. 8 degrees outside..lol.. This morning I ran out in the garage and bleed the foam off (30 seconds) and we're back up and running again. I'm going to update later as to what the final outcome is as while goggling I found others that seamed to have the same problem but never posted "the fix". If I had no choice but to go this myself w/o calling a tech today, I would make a 5 gallon tank and plumb that directly to the filter. This would let me isolate the problem to either the filter forward or the filter back to the tank. My unprofessional guess, pump is beating it to a foam from an obstruction in my line.

HVACNUT

Yeah, like lchmb said, speak to the service manager from your fuel delivery company. He should be able to do something for you. Don't beat him up too much about the OOO. It happens. Computer tracks degree days and messes up sometimes.
Maybe invest in a remote tank gauge like the Beckett Rocket so you can monitor your fuel level. Just be sure to set the dip switches on the receiver for your tank size and style. Not supposed to recommend products but I'm happy with mine.

STEVEusaPA

Don't forget you need a tube (clear tube is best) from the bleeder immersed into the oil, while bleeding.

EBEBRATT-Ed

Somehow, somewhere you have a suction leak. The more lift you have the more problems the suction leak causes.

I am surprised not to have herd the word "tiger loop" yet. LOL

chsapeak

Taking advice from so many on here, I decided to focus my attention this morning on the oil filter before I left for work. I removed the cartridge housing and the new filter looked super clean. I opened another filter package and replaced all three gaskets on my "new" filter housing with newer ones and put everything back together. This time I held the lines firmly in place and tighten the bolt on top as tight as I could get it. Didn't care if I broke the bolt as I had nothing to loose. I then bleed the system for the 700th time and fired her up. Well I called home at noon and the system was still running, just got home from work now (5:00) and it hasn't tripped yet. I'm keeping my fingers crossed but I think it was the filter housing sucking air as so many of you had said. I can't thank you all enough, this site is a great find with a great group of guys..:) I'll post tomorrow am wether it runs all night or night. Thanks Again,
Dale

EBEBRATT-Ed

@Hatterasguy , I know, I am actually surprised I have not been wacked for that 2 pipe suggestion. I doubt that I shall survive the night though. Either the two pipe or the dreaded tiger loop will get me.

maybe because I started my career doing nothing but burners for a few years I admit to being absolutely paranoid about suction leaks.

To me it's one of the worst problems their is. Back then we were always taught if the pump is above the oil level in the tank=2 pipe and ....no substitute for tight oil lines. Flared enough tubing til it makes your hands hurt.

EBEBRATT-Ed

@Hatterasguy , one friking little bitty pinhole taking in air is all it takes. I think even the pump mfgs advocate a one pipe system with lift.

and then to go along with the dreaded tiger loop and the dreaded two pipe system is the equally dreaded "return line leak"

STEVEusaPA

I've been working on oil heat for over 25 years. Almost all customers are one pipe. Many lift jobs, some even had compression fittings. When things are done right, there are no problems.
Two pipe and tiger loops are both band aids for improperly following the manufacturers instructions, and improper installation techniques.
Properly installed one pipe lift jobs are working fine and trouble free all over the world.
There is also nothing wrong with General filters. Yes of course spin ons filter better, but a properly installed General doesn't leak-fuel or vacuum.

EBEBRATT-Ed

To each his own. If I had my way every job would be 2 pipe. Less sludge problems and the pump and filter are constantly filtering the tank, no bleeding