Diagnostic questions & answers about the oil burner fuel unit or pump, set #2:

These FAQs pages answer common questions about the oil burner fuel unit or "oil pump" used on oil-fired heating equpment suchj as the oil burner for a heating boiler, furnace, or oil-fired water heater.

This article series explains the inspection, diagnosis, & repair of oil burners used in heating appliances such as hot water boilers, steam boilers, & water heaters.

Oil Burner Fuel Unit (oil pump) Diagnostic Questions & Answers

This article contains questions and answers regarding oil burner fuel units and is a companion to our lead article on this topic: OIL BURNER FUEL UNIT

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On 2018-01-01 by (mod) - got oil and my pipes are all cold no heat why

Caroline,

I can only guess, as I have no information about your heating system nor your building. But here are some possibilities

If you had run out of oil you may need a service call to get your oil burn air running again because there may be air or sludge in the oil lines and oil filter and fuel unit on the oil burner.

However if the oil burner seems to start and run normally but the heating pipes and baseboards or radiators never get hot then I suspect that your system is air bound.

You can search this website using the search box just above to look for that phrase Airbound heating pipes, to see how to diagnose and repair that problem.

See OIL BURNER WONT RUN for a flowchart of diagnostic steps for an oil burner that won't start or won't keep running: what to check in what order.

On 2018-01-01 by Caroline

I have a beckett furance got oil and my pipes are all cold no heat why

On 2017-12-30 by (mod) - is this time to replace the fuel unit or is this something I could 'free up' in some way?

Doug,

With the apology that I am obligated to point out that I can't be confident of a detail of diagnosis overheating system fuel unit based on a brief a text,

I will add that although it might be possible to disassemble and clean and repair a fuel unit with a stuck check valve, or some other internal problem, those are not things that any heating service tech would attempt in the field.

It's just more cost-efficient to swap in a new unit.

As we have warned elsewhere in these faqs,

Watch out: we do not reommend that you try disassembling a fuel unit unless you are trained to do so. Making a mistake could result in a leak, loss of heat, or worse, a building fire, injuries, or worse.

On 2017-12-30 by Doug

Thank you for your quick reply.

If it is a nonoperational value in the pump, is this time to replace the fuel unit or is this something I could 'free up' in some way?

The unit sometimes produced a short, shrill sound and one second burst of oil, but only once every third of fourth attempt (thank you for mentioning the fact that I could blow a seal, so I won't keep attempting this).

On 2017-12-29 by (mod) - fuel unit air leaks in or oil leaks out

Doug

It's normal to get lots of air out of oil piping right after changing an oil filter or disassembling the fuel unit. I'm assuming you got this at the air bleeder valve attached to a tube dumping foamy oil into a container. When the oil runs clear with absolutely no air bubbles it should have been successfully purged.

Of course a small leak can be subtle and recurrent and hard to find. But I'd not expect that to produce zero oil output at the high pressure port.

If no oil exits the high pressure line, and assuming you haven't fouled up the pressure adjustment on the fuel unit, then it sounds as if a valve in the pump is not operating. Don't keep running it as you could blow as seal and splash oil all over creation.

On 2017-12-29 22:28:41.489804 by Doug

Hello,
My Suntec fuel unit isn't sending oil through the high pressure line from the pump outlet to the oil burner nozzle assembly. I disassembled the fuel pump and the screen was clean. When bleeding the unit, there were a lot of small air bubbles (foam-like), even after two minutes of purging. This eventually gave way to a strong stream of oil, but still nothing coming from the high pressure line. Does this sound like a bad pump or is there a blockage of some kind?
The heating system has a Beckett burner and the whole system is about six years old.
Thank you in advance for any help you can offer.

On 2017-11-01 23:11:21.181059 by (mod) -

Joe,

it has been quite a while since I have installed one of the older Sunstrand fuel units but the last time I was up heating supplier replacement models were still available. I need to be sure to get the correct pump for the correct rotation direction.

On 2017-11-01 by Joe Coate - old Miller oil gun furnace

I have an old miller gun oil furnace, It has a oil pump sun stran J2CBF, CR1. I need to replace the pump, but I don't know where to find one. Do you suggest a replacement?

Thanks

On 2017-10-21 by (mod) - Do becket oil burner pumps have strainers in them..?

Charles,

Yes.

All of the current Beckett oil burner manuals, in discussing the oil burner fuel unit maintenance, include a cloudy statement

"Remove and replace the fuel unit strainer if applicable"

- which I take to mean IF you have disassembled and cleaned the fuel unit you should replace the strainer - something I was taught to do always at every service job, although I realize that overworked service techs often omit this step.

I have not found a fuel unit (oil burner pump) by Beckett, Carlin, or Webster or Sunstrand that did not include a strainer.

My photo shows the strainer in a Beckett Cleancut A2EA-6528 fuel unit (oil burner pump).

Watch out: when installing a new strainer in a fuel unit be sure the strainer is properly seated and that the four cap bolts are properly torqued. An air leak at this location can lead to loss of heat or even unsafe oil burner operation.

On 2017-10-21 by Charles kalemjian

Do Becket oil burner pumps have strainers in them..?

On 2017-02-25 by (mod) -

For those jet pumps that are convertible, usually the pump's front-end of its impeller assembly is removed and a one-line jet pump front end is bolted on.

You are asking about water pumps, not oil pumps on an oil burner.

See WATER PUMP, TWO LINE JET

On 2017-02-24 by Eddie

How do you convert a 2 line pump to a 1 line pump

On 2017-01-29 by Mayur phadtare

What is the prize of this pump

On 2016-10-28 by (mod) -

Check the internal bypass plug in the pump = your pump may be set-up for a one-line piping system. Watch out: making a mistake between 1 and 2 line pump setups can blow the fuel pump and cause a building fire.

On 2016-10-28 by sam

I put new pump n and new lines its a too line pump but still cant get to pump fuel i checked the round gear behind pump its fine

On 2016-10-25 by (mod) -

Mojo:

Causes & Cures for Oil Burner Combustion Chamber Flooding

A fuel-flooded oil burner fire box is more than nasty it's downright dangerous as a subesequent effort to re-start the burner can result in a PUFFBACK EXPLOSION (search InspectApedia for that term using the search box just above).

Depending on the age of your system and just what safety controls are installed, one of several types of flame sensors such as a cad cell relay or a stack relay is intended to shut down the oil burner motor and thus the fuel unit pump if no flame is established after 20-30 seconds, thus protecting against oil flooding. Several things can happen to mess this up:

1. The safety device may not be working - it doesn't shut off the oil burner motor

2. A homeowner might keep pressing the re-set button repeatedly, causing flooding of the combustion chamber

3. The controls might be working but a defective automagic shutoff valve within the fuel unit could be stuck open (typically from dirt on the valve seat inside the fuel unit).

That situation combined with an oil storage tank that's above ground and full enough to send oil to the oil burner by simple gravity could also flood the system.

You should

1. SHUT OFF the oil burner and leave it off IMMEDIATELY

2. SHUT OFF the oil fuel line into the burner - there should be a fusible-link oil line valve right at the oil burner or if not, on the oil line near the burner or at the oil tank

3. Call your heating company for repair. Be sure to tell the tech that the combustion chamber is flooded.

On 2016-10-25 by mojo

what would cause my furnace to flood the firebox with fuel? it was working normally, i shut it off and left for the weekend. when i returned , i noticed fuel oil on the floor of the shop. have fuel shut off at the tank until i can look into it further, but not sure where to start. any help? Beckett pump.

On 2016-10-10 by (mod) -

It'd be nice to diagnose the trouble before switching to an old oil burner or its parts, as I'm reluctant to blame the fuel unit.

First: I'd watch the flame during operation to see what it looks like when it stops. Is it increasingly smoky or does it suddenly peter out? Is there a clogged oil filter? Is crud building up on the electrodes? Will it re-start 30 seconds after shut-down or do things have to cool off longer?

On 2016-10-09 by Christopher

So I have the intermittent flame problem as well, only thing with mine being different is the burner fires of perfectly every time for about 15 minutes great flame couldn't be adjusted any better.

Cad cell is nice and snug and I roughed up the contacts on the back side of the contacts to make sure great connection. I have blown out oil tank plus lines to rule out debris, new tip, contacts are all realigned, new oil filter was also put on, new relay box put on, new thermostat, pump and electric drive motor sound no different on the burner,

now I have an old aero burner in my basement from an old furnace which I know the pump on it works great now the rpm speeds are the same at 1725 rpm can I just switch the two out? Regardless of brands, mounting holes seem to be the exact same size.

On 2016-02-25 by (mod) - possible causes of intermittent oil burner failure

Thanks for the interesting question, Chris. There are several possible causes of intermittent oil burner failure that I can name and probably others that your service tech can suggest but that I've not thought-of.

- An oil burner that needs cleaning and adjustment

- A loose wire

- A cad cell sensor that's loose in its mount or is failing

- Intermittent draft problems

- A fuel unit whose coupling to the drive motor through the blower fan in the oil burner may be developing a bearing or drive shaft failure or the coupling itself may be slipping

- water or debris in the oil tank, supply lines, filter, or fuel unit screen

- a failing transformr

Often an intermittent problem gets worse until it becomes a hard failure - not very convenient during the heating season, but easier to diagnose. I would prefer to find and fix the trouble rather than "shotgunning" by just starting to replace parts.

...

Continue reading at OIL BURNER FUEL UNIT - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

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• OIL BURNER FUEL UNIT - home
• OIL BURNER FUEL UNIT AIR BLEED PROCEDURE
• OIL BURNER FUEL UNIT ANNUAL MAINTENANCE, SERVICE & REPAIR PROCEDURES
• OIL BURNER INSPECTION & REPAIR home page for oil burner diagnosis and repair
• OIL BURNER MANUALS
• OIL BURNER WONT RUN - Diagnostic Steps - what to check in what order,
• BIODIESEL HEATING FUELS - separate article. Warnings about using biodiesel in older oil burners.

Suggested citation for this web page

OIL BURNER FUEL UNIT DIAGNOSTIC FAQs-2 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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