# Oil furnace won't prime after filter change



## av-geek (Jan 15, 2012)

Yesterday, I began prepping my forced air oil furnace for the season. I cleaned the heat exchanger, and changed the fuel filter. At the end of the season last year, I let the oil tank run dry, so I put about 20 gallons of diesel fuel in the tank from the service station just to get it running and all checked out before the oil man makes a delivery.

Now, I've performed the task of changing the fuel filter on my grandmother's furnace many times over the years. Her furnace is in a crawl space, and has a single oil line going to it. The oil tank is out in the yard behind the house, so it's higher than the furnace. The typical way I did hers was after replacing the filter and cleaning out the can, was to crack open the valve and let some oil run into the can, and fill up the new filter. I would then re-attach the filter, and priming up the burner was a sinch. 

This procedure however didn't work so good with mine. I've got a Rheem Lo-boy in the ground-level basement of my tri-level. The oil tank is outside at about the same level. After changing the filter, I opened the valve to let a little oil flow in...no oil! So, I figured the oil pump on the burner would suck some through. I put the filter together, cracked open the bleed valve, threw the switch, and nothing...3 resets later, I pulled the filter can back off to see if any oil had gotten through. It was still dry!

This is a one-line system. Will the burner "suck" the fuel from the tank if it's below the level of the burner? The tank was run completely dry, so I imagine the burner has some ability to do this, but I am wondering if I can get it started, or will I need to wait for the oil man to come with another 200 gallons or so to get the level in the tank high enough to flow out the line.


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## yuri (Nov 29, 2008)

Need more oil. They have 2 pipe systems for below the burner tanks and that allows them to pump some back to the tank so they have more lift. Don't run it dry too often or the pump can get damaged. You may also have crud inside the pump now and apparently some have a removable cleanable screen in the pump. Beenthere knows more about them. Post a closeup well lit pic of the burner and pump.


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## beenthere (Oct 11, 2008)

Cracked the bleeder open? As in barely open?


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## hpyjack2013 (Sep 16, 2013)

*oil filter won't prime after filter change.*

get yourself a bicycle pump , take out the cartridge re-install bowl gently blow air back into tank. let some oil run out to check flow.also disconnect line at filter and furnace and gently blow out line. re-install filter make sure gasket at filter bowl is new and tight and make sure strainer in pump if it has one is properly cleaned and cap gasket is in good shape and tight.


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## COLDIRON (Mar 15, 2009)

Send pictures as requested and put some more oil in that tank then find the blockage.

Sounds like it has to be in the line or shut off valve between the tank and the incoming side of the filter.

Tip never run a oil tank dry and shut down the burner when receiving oil until it settles.


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## av-geek (Jan 15, 2012)

fuel delivery is scheduled for tomorrow. I'll check the pump screen after the delivery, and see if I can get it primed up then. Thanks for the help guys! If I still don't get oil, I'll try pushing some air down the line back to the tank.


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## hpyjack2013 (Sep 16, 2013)

are you going to be there? make sure you have buttoned up everything you might have open or loosened before delivery-bleeders, gaskets etc.. you don't want it all over the floor. first thing I would check after delivery would be to take off filter bowl and see if you have a good flow. If not. a GENTLE tap on the open firomatic might start the flow. if that checks out, put filter back together and see if you can prime it at burner. it that checks out I would then check and clean pump strainer. nozzle???


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## Duckweather (Mar 26, 2012)

Is your filter on the tank? If any crud in the tank solidified while it was dry then the fitting from the filter to the tank could be blocked. If you fill the tank you will have 200 gallons of oil behind the blockage if you have to unscrew the filter fitting to clear it. I wouldn't want to be the one trying to thread it back in then.


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## hpyjack2013 (Sep 16, 2013)

didn't say unscrew the filter assembly. I said take off or unscrew the filter bowl, and there should be a firomatic valve between the filter assembly and the tank. so if the valve is working properly you should be able to close the valve and unscrew the whole filter assembly, which really isn't necessary the BOWL will do. be careful if this is an old tank they can become brittle and porous. keep an eye on the bottom.


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## av-geek (Jan 15, 2012)

Okay, oil man came today and put in 200 gallons. Tonight, I opened the valve and tried to get it to prime...nothing. I Took the filter off, as can be seen in this photo, opened the valve, and the weight of 200 gallons of oil couldn't get anything flowing, so there's probably an obstruction in the line somewhere. 

Another thing I noticed however was that I'm not getting any suction from the pump. I took the cover off the pump and cleaned the strainer in it. It was somewhat dirty, but not all too bad. After re-assembling it, I took the oil line off and while the burner was running, just stuck my finger on the open fitting...it was not sucking against my finger at all, nor was I getting any air spitting out the bleeder valve. 

...so it looks like I've got two problems. Tomorrow, I'm going to try and force some compressed air up the line, but it also looks like I'm going to need a new oil pump.

BTW, you may see that there's two lines there...the other one is NOT connected. It went to the old underground tank, and is not long enough to make it to the above-ground tank.


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## yuri (Nov 29, 2008)

Lesson to be learned. Try not to run out of oil. If it sat dry all Summer the air in the tank may have hardened the crud at the bottom. Don"t fill your car up while the delivery truck is filling the gas station tanks either as lots of crud gets stirred up. Go to the next one.


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## beenthere (Oct 11, 2008)

May have a broken pump coupling.

Does your line come out of the to of the tank, or the bottom.


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## COLDIRON (Mar 15, 2009)

Good question, does your line come off the bottom of the tank ? If it does is there a shut off valve right where it comes out ?


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## hpyjack2013 (Sep 16, 2013)

those pumps aren't vacuum pumps. they aren't necessarilly designed to "draw" a whole lot of suction. they rely on the flow of oil and gravity to do a lot of the work.establish your flow of oil first. bottom of the tank, side of the tank it really doesn't matter where the outlet is. yeah bottom will plug easier. make sure there is a shut off at the tank. disconnect the line at the tank and see if you can establish a good flow of oil there.remember be "gentle" old or new things happen. If you are going to use compressed air make sure pressure is set low. I used to use an old bicycle pump-nice and easy and gentle, once you establish a good flow of oil at tank. leave line disconnected , disconnect from burner and blow out line between burner and tank. re-establish flow of oil through line,before attaching line and it helps to clean out any sludge. make sure filter cartridge is the right one.bleed filter before tightening. -let oil flow out of sides then tighten filter bowl. make sure the gasket is good on pump strainer gasket. they are paper thin and don't leave much room for error. now try priming the pump. a short piece of flexible plastic tubing works great. let it run till you get a good stream. shut if off disconnect the nozzle line from the gun assembly loosen at at pump, swivel and run the pump again and see what you get for stream. let it run to make sure you are getting a good stream. shut it off and re-connect nozzle line , keep your fingers crossed and try firing of burner and hope the nozzle isn't plugged.don't try blowing out line with it connected to tank. make sure it is disconnected at opposite end. depending on how old line is you can rupture it. is buried or is it exposed?


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## av-geek (Jan 15, 2012)

Line comes out the bottom of the tank. That's a good suggestion! There is a valve on the line near the bottom of the tank...I may have turned that off last season. DUUH! Will check it tonight after work.

The whole intention I had last spring was to run all the oil out the tank before this unit was replaced. We were thinking we would have a sale of our old home,and would use the money to get a gas HVAC system, among other things. Well, the people renting it wanted to lease it for another year, so the oil furnace is getting a second life. Oh well, they are paying another year on my mortgage! Thankfully, it's been moderate around here, so this isn't an emergency yet.


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## COLDIRON (Mar 15, 2009)

av-geek said:


> Line comes out the bottom of the tank. That's a good suggestion! There is a valve on the line near the bottom of the tank...I may have turned that off last season. DUUH! Will check it tonight after work.
> 
> The whole intention I had last spring was to run all the oil out the tank before this unit was replaced. We were thinking we would have a sale of our old home,and would use the money to get a gas HVAC system, among other things. Well, the people renting it wanted to lease it for another year, so the oil furnace is getting a second life. Oh well, they are paying another year on my mortgage! Thankfully, it's been moderate around here, so this isn't an emergency yet.


Post back if the valve was closed.


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## hpyjack2013 (Sep 16, 2013)

what's that ol'sayin?: the road to hell is paved with good intentions!!??


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## FClef (May 5, 2013)

OK, first of all you have gotten good advice thus far.

One thing that I will warn you about, because I have seen it numerous times, is the fact that an outside tank with a valve on the bottom of the tank is an oil spill waiting to happen. Outside tanks are subject to more condensation than inside tanks which means that you will get water inside of them. If this water freezes in that valve it can crack and will eventually leak. Also, the valves typically stick out enough so that it can be sheered off if it gets hit with something... like ice falling from a gutter. The best thing to have with outside tanks is a line that comes off the top of the tank. Typically when the line is installed you run it to the bottom of the tank and pull it back up about two inches. This normally prevents you from picking up any sludge or water. If you do that kind of thing, putting in a second pipe isn't a bad idea so the pipe will self-prime which can be a problem when oil is delivered and the burner is running. The only way to get more lift out of your pump is to put in a "two stage" oil pump, as opposed to the single stage pump which is normally present on a burner. Use this chart: http://www.engineeringtoolbox.com/fuel-oil-pumps-d_1022.html to figure out if you really need a two stage pump.

I will admit that I am a little rusty with my oil burner technical information so the stuff about the pumps may be not so current, but the tank information and the lines is solid.

Let us know how you make out.


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## av-geek (Jan 15, 2012)

Okay, here's the verdict on what I found this evening when I got home...valve on tank was open, which means that we definitely have a blockage. I closed the valve, removed the line, and then cracked the valve open with a bucket underneath...I got nice clean, clear oil out the tank  That means the blockage isn't in the tank, but in the line somewhere between the furnace, and the oil tank. I'm going to leave the tank disconnected, and also disconnect it at the furnace, and then use compressed air on it. Not going to have enough time to do it tonight due to running sound at church for music practice, but will let you guys know what the next step is here!

Thanks for the advice HappyJack on the bottom valve! This system has to last hopefully only one more season then it's outta here! I would definitely be modifying the tank if it was staying. The furnace is over 25 years old, and the gas service offers free hookups if a new furnace is installed. Once we sell our old house, we are using the money to get a new gas furnace and AC system installed. My father in law does want the old system to heat his garage, so before it's taken over there, I'll probably do that!


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## FClef (May 5, 2013)

av-geek said:


> Okay, here's the verdict on what I found this evening when I got home...valve on tank was open, which means that we definitely have a blockage. I closed the valve, removed the line, and then cracked the valve open with a bucket underneath...I got nice clean, clear oil out the tank  That means the blockage isn't in the tank, but in the line somewhere between the furnace, and the oil tank. I'm going to leave the tank disconnected, and also disconnect it at the furnace, and then use compressed air on it. Not going to have enough time to do it tonight due to running sound at church for music practice, but will let you guys know what the next step is here!
> 
> Thanks for the advice HappyJack on the bottom valve! This system has to last hopefully only one more season then it's outta here! I would definitely be modifying the tank if it was staying. The furnace is over 25 years old, and the gas service offers free hookups if a new furnace is installed. Once we sell our old house, we are using the money to get a new gas furnace and AC system installed. My father in law does want the old system to heat his garage, so before it's taken over there, I'll probably do that!


Great news!

Please use caution with the compressed air. You don't need much pressure to clear the line. The very last thing you want to do is to burst the line from blowing it out.


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## beenthere (Oct 11, 2008)

Or blowing oil all over anything outside the house.


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## FClef (May 5, 2013)

beenthere said:


> Or blowing oil all over anything outside the house.


Oh the way we have learned things, eh? School of hard knocks and all that.:laughing:


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## beenthere (Oct 11, 2008)

FClef said:


> Oh the way we have learned things, eh? School of hard knocks and all that.:laughing:


LOL, yeah, some mistakes aren't as funny when you make them, as they are 30 plus years later. LOL


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## yuri (Nov 29, 2008)

Like the time I am fixing this small oil boiler on a paddlewheel boat. Used to heat the tourist space inside. Boiler is situated outside about 1 foot from the paddlewheel and 6" from the Red River. Could not get any oil, 2 pipe system, changed the pump, same thing, got another pump. Boat is about to sail with me and my butt 6" from the Red River. Who knew the oil came from the same diesel tank as for the paddlewheel and the mechanic shut it off earlier that day when workin on the engine. Nobody told me.:no:


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## bobinphx (Nov 25, 2011)

or the time I replaced the bearings on an indoor fan motor (back when you could do this and it was a cheap fix)..and got the motor end plates on the wrong ends and the motor ran backwards... was not funny then.. is now!!!!!!


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## yuri (Nov 29, 2008)

Uh hah. And the first time I changed an oil burner motor. Fired er up and no oil from the nozzle. Changed the nozzle, no oil, changed the pump. No oil. Put another pump on, no oil. Nobody told me those motors had 2 rotations. CW and CCW. Finally figured it out. That what happens when you are 18 and think you know everything.:laughing:


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## COLDIRON (Mar 15, 2009)

The time I pushed the red reset button on a Firehouse Boiler 2 many times and it blew up. It's a long story I told before. Glad I listened to some of the stuff the old guys told me. Always stand to the side of electrical panels, boilers, pumps, compressors ,etc., etc. when starting them. To bad I didn't listen to everything they told me. Only push the red reset button once or possibly twice. DuH!!!!


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## taxmantoo (Jun 11, 2013)

COLDIRON said:


> The time I pushed the red reset button on a Firehouse Boiler 2 many times and it blew up.


I did that once, then called a tech without telling him I hit the button 5-10 times. (he didn't ask, and I didn't know it was an issue) He serviced the burner, had me turn the thermostat on, and we listened to the flue roar as we saw flames peeking through little gaps in the elbows. It burned itself out less than a minute after he convinced me to call 9-1-1. Not the recommended way to clean the soot out of the chimney.


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## yuri (Nov 29, 2008)

Yep. I learned the hard way to never trust the customer about that after having a flooded not just wet unit take off on me. Had to call the fire dept and it took 1/2 an hr to burn out that oil. Heat ex was red hot and the venting tuned white hot.


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## yuri (Nov 29, 2008)

COLDIRON said:


> The time I pushed the red reset button on a Firehouse Boiler 2 many times and it blew up. It's a long story I told before. Glad I listened to some of the stuff the old guys told me. Always stand to the side of electrical panels, boilers, pumps, compressors ,etc., etc. when starting them. To bad I didn't listen to everything they told me. Only push the red reset button once or possibly twice. DuH!!!!


GOOD point about standing to the side of equipment. ESPECIALLY a AC compressor if it could be grounded or shorted. I have had several fusite plugs blow and oil and acid and burning freon fumes come shooting out.


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## beenthere (Oct 11, 2008)

When customer says they only pushed the reset button once. its often best to take that as only pushed the reset button once too often.


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## yuri (Nov 29, 2008)

I got to the point I would look em straight in the eye and add 2 to 3X what they told me.

That stupid flooded furnace was some bizarre Shell furnace with a steel square combustion chamber with no regular round brick chamber. There was a space between it and the actual heat exchanger and the oil got behind it so I could not see it. Strange very rare furnace which you may never have seen.


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## beenthere (Oct 11, 2008)

I have a round steel combustion chamber(no bricks). Its an American Standard.


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## av-geek (Jan 15, 2012)

We have IGNITION!!! WooHoo! 

Nice warm sunny day out today, so I got into the oil lines. Disconnected from the tank, and from the furnace. Got a blow gun on my air compressor, and just stuck the tip down in the line on the furnace end. I threw a rag over the open end at the tank, and put a bucket under it. All sorts of black and brown grimy gunk came out the line. Looked like crankcase oil that came out of a car with a bad head gasket. Glad I didn't get that in the furnace!

Well, I connected everything back up, and still couldn't get a siphon started...the pump just doesn't have enough sucttion. Then, a bright idea hit me. I used a syringe to bleed the hydraulic clutch on my SAAB 900. I had another spare syringe around. I stuck the syringe on the bleeder nipple with the burner off, and drew it up to suck the fuel down the line with a little more authority. I got a couple air pockets out, and then nice clear, clean oil. With a flip of the switch, oil started flowing out the bleeder port. I closed the bleeder port and VWOOMP!    FIRE :clap: and that lovely smell of the dust burning off a hot heat exchanger filled the house


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## COLDIRON (Mar 15, 2009)

av-geek said:


> We have IGNITION!!! WooHoo!
> 
> Nice warm sunny day out today, so I got into the oil lines. Disconnected from the tank, and from the furnace. Got a blow gun on my air compressor, and just stuck the tip down in the line on the furnace end. I threw a rag over the open end at the tank, and put a bucket under it. All sorts of black and brown grimy gunk came out the line. Looked like crankcase oil that came out of a car with a bad head gasket. Glad I didn't get that in the furnace!
> 
> Well, I connected everything back up, and still couldn't get a siphon started...the pump just doesn't have enough sucttion. Then, a bright idea hit me. I used a syringe to bleed the hydraulic clutch on my SAAB 900. I had another spare syringe around. I stuck the syringe on the bleeder nipple with the burner off, and drew it up to suck the fuel down the line with a little more authority. I got a couple air pockets out, and then nice clear, clean oil. With a flip of the switch, oil started flowing out the bleeder port. I closed the bleeder port and VWOOMP!    FIRE :clap: and that lovely smell of the dust burning off a hot heat exchanger filled the house


:thumbup::thumbup::thumbup::thumbup::thumbup:


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## Duckweather (Mar 26, 2012)

Necessity is the mother of invention.


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## hpyjack2013 (Sep 16, 2013)

glad to hear you got it to work. some things to think about before you replace the pump, did you let the oil flow through the line from the tank to the filter housing with the filter bowl off to see if you had a good flow and to help flush out any residual residue? It can take take a couple of cycles to get the air removed. Did you soak the filter in oil before installing it in the filter bowl?? whole time that is running the oil is being absorbed by the filter. and bowl has to fill before oil comes out of bleeder valve.If you think the pump is weak, which I doubt, keep an eye on it. make sure it doesn't allow oil to leak or seep by into the combustion chamber. (Don't feel like reading everything again). did you ever establish if the was a pump strainer and if it needed to be cleaned. make sure all your connections are good and snug. Lastly at the end of the line there is a nozzle with a strainer, based on what you have seen what do you figure that looks like.


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## scottgoodson (Nov 14, 2013)

i put anew fuel pump an a new coupling in between pump an motor on my oil furnace an now it wont bleed do i need to prime the line


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## beenthere (Oct 11, 2008)

Are you getting ir out of the bleeder. How long/many times did you bleed it.


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## hpyjack2013 (Sep 16, 2013)

make sure you got the shaft or adapters on both motor end and pump end. Isn't filter at pump end? check for flow at filter. If tank is full you should get a flow. Is pump the exact replacement? rotation etc? check all fitting for snugness.


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## franzenl187 (12 mo ago)

COLDIRON said:


> Send pictures as requested and put some more oil in that tank then find the blockage.
> 
> Sounds like it has to be in the line or shut off valve between the tank and the incoming side of the filter.
> 
> Tip never run a oil tank dry and shut down the burner when receiving oil until it settles.


I didn't **** the furnace off and took filter off


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## roughneck (Nov 28, 2014)

franzenl187 said:


> I didn't **** the furnace off and took filter off


Your quoting a 9 year old post, made by a poster that hasn’t logged on to the site in 2 years. 
Do you have a problem? Are you trying to solve an issue? 
You’ll need to start your own thread.


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