debugging air in fuel line

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  #1  
Old 02-28-15, 11:27 PM
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debugging air in fuel line

I have a diesel water heater that has been acting up in mildly cold weather, ~40 F to 26 F. air seemed to increase in the line as the weather got colder which would cause the becketburner to reset. at first if I reset it then it would run off and on for a few hours. now it can only run for a minute, then I have to bleed the line again. The bleed spout is on the beckett burner a few feet down the line from the fuel filter. In that few feet there is 18 to 12 inches of rubber(?) pipe secured with flathead tightened pipe clamps between a metal pipe and the beckett. Does a leak in the pipe or fuel filter seal seem reasonable as the cause of the air or could it be more likely something within the beckett burner itself?
 
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Old 03-01-15, 12:06 AM
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How far is the fuel tank from the burner? Is there a screen filter besides the regular filter, on the side of the burner? Are the screws loose? I had a similar problem on a oil burner. The tank was 60 feet away & it was a strain for the burner to pull the oil.
 
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Old 03-01-15, 10:10 AM
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In that few feet there is 18 to 12 inches of rubber(?) pipe secured with flathead tightened pipe clamps between a metal pipe and the beckett
For starters, this is totally unacceptable.

OR, are you talking about a braided metal 'flex line' that is made for the purpose? Of course, if it were this, you wouldn't be mentioning pipe clamps at all.

When was the last time the burner was serviced?
 
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Old 03-01-15, 10:21 AM
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The tank is probably 200 ft or more from the burner. I will check screws again. Where would the screen filter be?
 
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Old 03-01-15, 10:29 AM
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What is unacceptable? The line? I think I know the piping you mean, rubber mesh and rubber. I think that is it. Will try to get a photo some how.

I inherited the setup from my late father. It has probably never been professionally serviced.
 
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Old 03-01-15, 10:38 AM
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200' is a pretty far distance to have a burner pull from. Why so far away?
Is this an inground or above ground tank ?

The guys are trying to find out what is in the fuel line between the tank and the burner.
You mentioned fuel filter and that patched line.... is there anything else ?
 
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Old 03-01-15, 10:59 AM
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It's above ground. I think it's far because more room was needed to let a truck fill the tank. I think it's 500 gallons. I think it goes like this:

500 gallon Tank
pipe from bottom of tank 3/4"
valve
pipe 3/4"
elbow
long run of pipe underground 3/4 "
elbow
pipe up out of ground 3/4 "
elbow
pipe 3/4 "
filter fitting with Napa fuel filter screwed in
pipe 1/2"
valve
pipe 1/2 "
fitting to downsize to nipple
tubing attached with hose clamp
tubing
tubing attached with hose clamp
beckett burner

Looks like the flex pipe goes right into fuel pump... suntec a2va-7116

3gph for 100 to 150 psi
2gph for 150 to 200 psi
 
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Old 03-01-15, 11:06 AM
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The ONLY 'flexible' line you should have is one like this:



You need to get rid of that rubber hose with hose clamps for starters.

3/4" pipe? really? what type of pipe? how did you measure 3/4" ?

I would bet you've got all kinds of air leaks.

If that burner has never been serviced, it needs to be done.
 
  #9  
Old 03-01-15, 11:22 AM
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well the smaller piece of pipe has a valve that is clearly labeled 1/2 " so i deduced the larger version is 3/4 " not sure how relevant that is ... it could be 1 " but I'm pretty confident it's 3/4" and it's all metal I don't know enough to be more specific

OK can you give me some nomenclature to look for the flexible hose? I might see what Napa has. The ends screw on? Do I need a putty or sealant? And this is all for diesel?
 
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Old 03-01-15, 11:27 AM
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Just to clarify the unit is a commercial water heater used in a small farm so that's why it's probably a hack job. It does need to be serviced and probably the heater tank needs to be replaced. Now isn't the best time for that though. But it's not a residential setup.
 
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Old 03-01-15, 11:31 AM
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can you give me some nomenclature to look for the flexible hose? I might see what Napa has. The ends screw on? Do I need a putty or sealant? And this is all for diesel?
NAPA won't have those hoses.

Patriot Supply - S220-36

You will need the PROPER adapters to connect it.

Diesel is the same thing as #2 fuel oil without the red dye. If you are buying diesel, you are probably paying ROAD TAXES included in the price of the oil.

Why are you not burning #2 fuel oil? Maybe no suppliers in CA ?

Keep in mind that this flexible hose may or may NOT be the source of your trouble, especially since you say the burner has never been serviced to your knowledge.
 
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Old 03-01-15, 11:32 AM
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http://imgur.com/ICS41g9

you can see the tank is in mint condition
 
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Old 03-01-15, 11:48 AM
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I can? You mean the oil tank? Can't see it in that pic.

Is this stuff all outside?
 
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Old 03-01-15, 11:52 AM
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Was a joke about the water heater wall rusting. No the heater and picture are inside a structure. The fuel tank is metal (painted) and outside. I ordered the hose. Thanks for the help. I will try to determine the connectors.
 
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Old 03-01-15, 11:57 AM
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Ohhhhhh... ok, I'm chuckling now!

You should order the fittings from the same place...

Like I said though, the burner needs service. New nozzle, change filter screen, adjust electrodes, brush and vacuum the heat exchanger...

But, that brings to mind an old joke...

Tour guide: "Have you seen the Taj Mahal yet?"

Tourist: "No, I haven't!"

Tour guide: " Oh you must, it won't be there much longer, they're cleaning it."

Ba dum bum.
 
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Old 03-01-15, 12:09 PM
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dogowner, the screen is on the side of the burner itself. I lived in a place where the tank was only 60' from the burner & even that was way too much of a pull, for the burner. In your case, there has to be a union in the line between the tank & the burner. It can't be all one piece. Air could enter there as well.
 
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Old 03-04-15, 09:59 AM
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As far as I can tell my suntec pump cap is fused onto the bottom piece of the unit. I'm thinking rather than hammering the cap off with a hammer while the bottom is in a vice and then having a obliterated gasket and who knows what else that I should just replace the whole unit. Although it does look rather new. I'm not really sure how to separate the cap other than taking the 4 screws out. Is there a screw on the shaft side somewhere?

If the filter is plugged would that cause it to pump mostly air ? I'm starting to think there is a bunch of sludge at the bottom of the tank getting into the outlet. There is just a valve though and no way to clean it out. You'd think the smart place to put a filter would be there. Also the diesel doesn't free flow out of the fuel filter socket even when the tank is open and it sure seems like it should be a gravity fed system. There are about 250 gallons in the tank and I'd think even if I was marginally higher elevation that would cause flow.

The pipe is underground so I'd have to dig it up to find all the unions. Trying to cross off everything before that.
 
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Old 03-04-15, 10:26 AM
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There are hand pumps available that you connect to the line right before the filter. They suck the fuel through the line & eliminate the air. Then you reconnect the line, start the burner & bleed it. After that, you'll see if it stays running or if air reenters the line.
 
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Old 03-04-15, 11:01 AM
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Don't disassemble the pump unless you have a new screen and gasket on hand already.
 
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Old 03-04-15, 11:22 AM
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To get the pump apart take a thin screwdriver and hammer and carefully separate the pump at the seam.
Once you break the seal it will come right apart.
There's no sense getting another pump because you can't get that one apart because they'll be a screen in the new one also. So unless you actually need a new one be patient and open this one up.
 
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Old 03-11-15, 01:05 PM
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update: hose arrived

the hose has arrived, can I just feed it right into the pump inlet directly? the double male piece came with the hose

also i purchased a black iron 1/2 to 1/4 inch converter, as seen in photo, that should work right? all that junk on it is my poor job of using rector seal soft set

also i was lazy and just got a whole new pump, I'm hoping I can connect it without ruining everything, looks like i will have to transfer the shaft that connects to the motor from the old pump

http://imgur.com/kq2cecp,pgGfjCY#0

http://imgur.com/kq2cecp,pgGfjCY#1
 
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Old 03-11-15, 02:41 PM
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can I just feed it right into the pump inlet directly? the double male piece came with the hose
Sure, why not?

1/2 to 1/4 inch converter, as seen in photo, that should work right?
Sure, as long as it don't leak.

also i was lazy and just got a whole new pump, I'm hoping I can connect it without ruining everything, looks like i will have to transfer the shaft that connects to the motor from the old pump
When you say "shaft", do you mean 'coupler'?

This part?



You could reuse it I suppose, but inspect carefully for cracks in the plastic etc... they are usually replaced whenever the burner is taken apart, it's just good practice for a cheapo part.

Beckett part number 2454. BUT, I'm presuming that this is an Beckett AFG burner? Other burners will of course use different couplers.

There are 'universal' replacements too, but be very careful that you cut it to the correct length!

If it's too short it will rattle around and break prematurely, if too long it will ruin the pump and/or the motor.
 

Last edited by NJT; 03-11-15 at 03:15 PM.
  #23  
Old 03-11-15, 02:43 PM
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With that long pipe to the tank you might have trouble getting that new pump primed and pumping. If you can figure a way to fill the pump with fuel first it would be a good thing.
 
  #24  
Old 04-08-15, 01:04 AM
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update 2

The burner seems to be running steady/strong now after replacing the whole fuel pump and the pump flex fuel line. The burn was unsteady before, sputtering, so I am hoping it was just the filter in the pump and not the underground fuel line. So ... success!

But now like the unwritten end of every success story I have new problems. Quick recap I have a complicated, at least to me, farm water heating setup for a closed loop radiator type system. The heat sources are diesel water heater and solar piping in roof.

1. The burner runs for 5 minutes but stops even though power to it is on. I think the pump is dead or there is a lot of air in tank causing it to rush to the Aqua stat setting at 160.
2. Actually Pretty sure the taco pump is dead that draws from hot water heater but i replaced it 3 months ago. No easy way to drain system to try to replace cartridge. Sounded really loud . Stopped it and started it. Noise got real loud and a clang and then nothing because I think it seized.
3. Pretty sure tanks need to be flushed but there is no drain spout or easy input spout to refill in isolation .
4. No isolated air release mechanism when trying to refill system. So I have to feed in water in small batches and run circulator pumps in succession to get it between 3 tanks with one air outlet at top of system that often is above water input to lower air pockets.

I think the time has come to just re plumb the whole thing. It is mostly cast iron leading to pvc for low temp warm water. I'd like to move circulater pumps between valves, add temp gauges, spouts for input and drain for tanks, bunch of shutoffs for isolation and some automatic air release.

Questions:
Is there anything easier to work with than iron pipes... directly around heater? Almost looks like I'll have to use carbon blade to cut piping off to even start making any changes. Then I'll have to thread a billion pieces.
 
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