Heating oil piping leaks in the oil burner supply & return piping: causes & effects of leaks in heating oil supply piping at fittings, valves, or other locations.

Heating oil pipe leaks out (fuel oil leaks), oil piping leaks in (air in the system) are dangerous in several regards, as a leak in oil burner feed piping can cause a puffback or complete loss of heat.

This document lists other important safety or oil-fired equipment operational defects in home and light commercial heating oil storage and piping systems.

Heating Oil Line Leak Troubleshooting FAQs

These questions & answers about leaks in the oil piping line(s) between an oil storage tank and the oil burner(s) were posted originally at OIL SUPPLY LINE PIPING LEAKS - be sure to see the diagnostic and repair tips given there.

Watch out: leaks in heating oil appliance piping or filters can lead to loss of heat, recurrent service calls, and even dangerous PUFFBACKS, OIL BURNER

On 2017-12-30 by (mod) - signs of an air leak in oil piping

Most likely there is an air leak somewhere in your oil line piping

On 2017-12-28 by Jose

Hello there. I'm hoping to get some insight into an issue I'm having with my oil burning furnace. So the problem I'm having is loss of vacuum in my oil line. I have a single line system and it is connected in the following way:

Starting at the tank outside the line comes out the top about 4 feet up and turns 90 degrees to pass through the exterior wall into our washroom where the furnace is located. So the line that is inside the room runs at the same height for about 3 more feet. It the passes through a shutoff valve which is directly connected to an old filter housing.

Then the line runs about 1 more foot and drops down about 3 feet into a trap curve. From there it runs about 7 more feet at a slow decline until it is pretty much sitting on the ground which then turns up for about a foot and a half that connects to the pump.

Just to add to the info available when we moved into this house the owners believed that the oil tank was about half full of oil.

This was in the summer so we didn't really worry about it to much. Well now that its winter and we have started using it, it turns out that there was a thin layer of oil but everything else bellow that was water

. I have since replaced the copper lines (which is the run I previously mentioned), the fittings, the flaring on the pipes and the oil filter insert (Not the actual canister). I have also pumped the tank and removed the water from it. I have completely cleaned out the pump of all junk and it is spotless now. I replaced the air filters recently as well.

So here is where it gets tricky. Because this was a surprise expense we don't have the upfront cash to get the tank filled.

So what I did was put a disconnect in the horizontal run before the line goes into the exterior wall. That way I can hook up a line going into a smaller 5 gallon tank that I can put off-road diesel in to hold us over until next year. I know it’s not economical but it’s all I can do right now.

Now... the problem. Running the unit seems to be working just fine. I prime the system, close up the bleed valve and start it up. Flame on, works great every single time but I have to prime it... every... single... time...

Any time the system shuts down because the temperature is reached in the home it sits for about 30 min to an hour.

Then when it's time to come back on the line has created a very large air pocket. When I go to purge the line after this happens I get about 2 seconds of oil, then it quickly becomes frothy for the next 2 seconds, then it just dies out for about 3 seconds. Then it finally catches the oil and froths for about 5 seconds and then turns to a good stream of oil.

Once the unit stops purging I close the bleed valve and start it up and it works just fine.

So after this happened a few times I decided to test something out. I ran the heat and when it finally got to the temperature I wanted I cut the heat off and then closed the shut off valve that sits before the oil filter. I figured I could find out if there was a leak in the filter if I let it sit for a few hours.

So I went back out to my shutoff valve. Brought up my remote thermostat app on my phone and turned the heat on. I opened the shutoff valve right before I started my heat up and low and behold the furnace lit right up. I didn't have to purge it at all.

So... with all that being said, does anyone have any ideas as to where my problem could be?

I just ordered a newer oil filter since that is a pretty cheap route to look into. Would fuel being pulled from a small tank pose this problem?

I would think that as long as the pipe stays submerged in the oil it should create a vacuum and not allow the oil to back flow into the oil tank.

Any advice you can provide is greatly appreciated.

On 2017-01-10 by (mod) - can I fit copper pipe direct to burner pump?

no you will need a flare fitting to connect copper to a threaded fitting that connects to the fuel unit and you should also install an oil filter and a fire-safety valve at the burner.

On 2017-01-10 by Henry

can i fit copper pipe direct to burner pump

On 2016-11-23 by (mod) - fuel oil furnace is leaking gel oil right at the in-take pipe

you either have to disassemble and remake the connection with pipe sealant rated for use on oil piping systems, or if the leak is minor you might make a temporary fix by cleaning the surfaces and applying an epoxy sealant

On 2016-11-22 by Megan

My fuel oil furnace is leaking gel oil right at the in-take pipe. Assume their air in the line. How do I fix this?

On 2016-10-04 by (mod) - how long do brass oil pipes last?

Paul:

I think you mean copper oil piping as that's far more common than brass.

Copper oil lines can easily last 50 years or longer if the piping is properly installed and protected.

Abrasion from vibration, failure to protect the piping from mechanical damage, burial directly in concrete, burial in corrosive soils can of course mean a shorter life.

On 2016-10-04 by David

How long do brass pipes (oil lines) last before there's corrosion ?

On 2016-03-26 by (mod) -

You need to find and fix the air leak in the line

On 2016-03-25 by (mod) -

Paul:

I suspect there is an air leak somewhere in your oil piping system.

On 2016-03-25 by (mod) - you can repair a section of flexible copper tubing or piping for your oil burner fuel line.

Yes Paul you can repair a section of flexible copper tubing or piping for your oil burner fuel line. Use two flare fittings.

But take care: a proper flare fitting requires some attention to detail. You'll need a cutting tool to cut the tubing, a pair of reamers to remove the internal and external tubing end burring that occurs during cutting, and a tubing flaring tool plus some instruction in how to use it.

Making an inadequate or poorly-made flare connection has results ranging from troublesome (oil leaks out, air leaks in, loss of heat) to dangerous (puffback explosion due to chronic air leaks). The flared end of the tubing has to be of proper size for the flare fittings - too big and it won't fit in the fitting, too small and it may leak.

See https://inspectapedia.com/plumbing/Gas_Leak_Detection.php for some photos and examples of copper flare fitting snafus.

On 2016-03-25 by paul

I have to keep bleeding my fuel line it runs fine but if it sits idol for a hour I have to bleed it again? checked for leaks didn't fine any, new filter, so any ideas?

On 2016-03-24 7 by Roy B

I discovered a kink in the soft copper line outside the house between the tank and where the line enters the house. Can I splice the line and if so with what type of fitting? If not, it would involve replacing 30 feet of copper unless other materials can be used. Thank you.

On 2016-01-21 by (mod) - The lift of oil burner fuel units is limited

Gary

The lift of oil burner fuel units is limited - you'll need a two-line oil piping sysetm. That may be enough, if not you'll add a lift pump.

On 2016-01-21 by Gary Jennings

Can an oil furnace pull oil from two floors below?

On 2015-09-08 by (mod) -

Joe, excerpting from our discussion of the Tiger Loop oil line deaerator

at OIL SUPPLY & RETURN LINE DE-AERATORS Tigerloop™

Tigerloop™ and other Oil Line Devices to Maintain Prime and Simplify Oil Piping

Tigerloop oil line foam and air remover (C) Tigerloop If your oil burner uses a Tigerloop™ oil-line de-aerator (photo at left) to remove air or foam from the incoming oil line, the company notes that UL requires a fusible link oil valve installed in the (bottom) center (inlet) port of the Tigerloop™ device.
Tigerloop™ is an oil de-aerator installed at the oil pump (fuel unit) on an oil burner. It can help avoid losing prime on heating oil lines if there is a problem with air leakage into the oil piping.

Watch out: Tigerloop™ adds that you should never install an oil line shutoff device between the de-aerator device and the oil pump. Shown is the Tigerloop S220. A variation is available, the Tigerloop-ultra™ S-220-8 that incorporates an oil filter as well.

The manufacturer, Westwood, indicates in an article quoted from Fuel Oil News magazine that using the Tigerloop™ model TN device permits omission of the return oil pipe traditionally used with buried or distant heating oil tanks.

Also see OIL LINE SAFETY VALVES, OSVs for more information about check valves, fusible link safety valves, and oil line de-aerators

Watch out: Tigerloop™ warns that you should never install an oil line shutoff device between the de-aerator device and the oil pump.

Or as reader T.R. clarifies: ... I've been reading about TigerLoop oil fuel line de-aerators. When they are used, the manufacturer recommends that the fusible valve near the burner be attached at the inlet of their de-aeration device.

Details about a suspected leak in oil line piping where a de-aerator or oil line air removal device is installed are in a Q&A discussion found at OIL LINE PIPING LEAKS or select a topic from the More Reading links shown below.

SEE FIRE SAFETY CONTROLS

On 2015-09-08 y Joe

Can a tiger loop be installed when the oil tank is outside above ground with a bottom feed a the burner is in the basement?

Question: how to seal off an unused copper oil line

(July 6, 2014) lee said:
I have a 2 line system one of the line leaking.

I can setup as a 1line no problem but I need to seal off the leaking one ! wondering if there is anything I can put into that line that would not break down with the fuel and save me from having to dig up the second line caulking ?

Reply:

Lee,

to close off a copper oil line without creating a future mess the best approach is to simply buy a flare fitting and a flare-threaded plug that will screw into the fitting.

Using a flaring tool, install the flare collar, flare the tubing end, install the flare fitting and screw the collar tight; then screw the flare threaded plug into the flare fitting.

All of these few parts (and the tool if necessary) can be obtained at a local plumbing supplier. You simply need to measure the OD of your oil line so that you buy the correct flare fittings - 3/8" or 1/2" for example.

Question: oil puddles or leaks around the oil burner

(Feb 8, 2014) Anonymous said:

I ALWAYS FIND OIL AROUND MY BURNER, WHAT COULD BE THE PROBLEM

Reply:

Anon, sounds like an oil leak. Leaks can occur inside the burner tube and drip out as well as anywhere in the fuel system .

Watch out, a leak out can also Involve air leaks in, leading to poor operation, loss of heat, or even a puffback explosion. Other than the petty crime of shouting in all CAPS, there is probably an oil leak at a fitting on or near the oil burner.

Watch out: oil leaks cause improper and unsafe oil burner operation as air can be drawn into the piping system leading to sooting, clogs, and a dangerous puffback. Ask your oil heating service company to inspect, find and fix the leaks.

...

Continue reading at OIL SUPPLY LINE PIPING LEAKS - topic home or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

OIL LINE PIPING - home

• OIL LINE AIR REMOVAL PROCEDURE
• OIL SUPPLY & RETURN LINE CONTROLS & VALVES
• OIL SUPPLY LINE PIPING LEAKS
• OIL LINE PIPING LEAK CAUSES
• OIL LINE QUICK STOP VALVES
• OIL SUPPLY LINE SAFETY VALVES, OSVs
• OIL LINE VACUUM & PRESSURE TESTS

OIL or GAS FUELED HEATING EQUIPMENT SHUTOFFS

OIL SPILL CLEANUP / PREVENTION

OIL TANK PIPING & PIPING DEFECTS - home

Suggested citation for this web page

OIL LINE PIPING LEAK FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to HEATING OIL, OIL BURNERS, OIL FIRED HEATERS, OIL TANKS

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