Heating Oil Filter Hell!!! (Need some input)


Hi Dominick,

I am a DYIer with lots of experience/practice. Recently, due to budgetary constraints, I decided to learn how to “tune up” my heating system and hot water heater. There has been no problem with replacing the nozzles, cleaning the systems out, adjusting the measurements of nozzle and electrodes…

My one problem is stumping me. I replaced the oil filter, and the air will not bleed out of the oil. It continues to come out “frothy” from the bleeder, and the button pops on both burners (due the the air.) When I put the old extremely dirty gunky filter back in the canister, the system bled properly, and both burners stay on.

Here are some specs:

Oil Filter Canister: Unifilter 99 which uses a 101 filter replacement.

New Filter: Wool Felt with metal mesh screen (101 replacement manufactured from Unifilter)

Old Filter: Don’t know type/brand because it was installed by my old oil company a couple of years ago (so it desperately needs changing!) It has a “star” or “gear” configuration w/o the metal mesh. Might be an RF-2 Micron filter.

Fuel type: #2 home heating oil (live on Long Island NY.)

Burners: Both are Beckett AFG type burners.

Nozzles: .65-80A

There are no kinks in the lines, and as far as I can tell all fittings are tight.

As long as the new filter was in, I was getting a lot of froth during the bleeding stage. I must have bled about a gallon of oil in trying to resolve the issue. I’m guessing it is a flow rate issue with the filter, but do not know enough about flow rates for my system to resolve problem.

If you need any other specs, please let me know. I have the Beckett manual, so I can look up / measure any specs you might need.

Do you have any advice?

Any help you could provide would be truly appreciated.

Thank you,

Joe Mastrosanti


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Joe Mastrosanti 3 years 7 Answers 723 views 0

Answers ( 7 )

  1. Awesome, glad I could help shine some light on it for you.

  2. Hi Dominick,

    Definitively knowing that this issue was an air leak made troubleshooting a breeze.

    I was able to make sure that all was seated properly. The issue, I believe, was that I might have been over tightening a bit. I didn’t think I was, but when I backed off half a turn the frothing stopped.

    It’s been over two hours with no leaks and the burners are running fine. I’ll check again tomorrow for leaks, but otherwise I’m all set.

    Thank you for the assist. It was driving me crazy. You have made my week.

    All the Best,


  3. Awesome let me know. I’m in Orange County NY. Up state from you.

  4. Thank you for the information. Your response helps me to rule out other issues. So, I guess the type of filter does not matter as long as it fits properly.

    I’m starting to wonder if the new filter was tight and putting pressure on the bottom bolt assembly. Just enough to allow some air to seep through. I’ll check that out.

    Either way I’ll get back to you. I know when I help folks out I like to get feedback.

    BTW, looked you up, saw you were from NY. We could be neighbors for all I know. I’m in Seaford LI. Nice to “meet” you.


  5. I would agree with you. However no matter what you have an air leak. Where is the big question?  What about the heights between the old and new filters? If the new one is longer than you may not be getting it tight enough to the lid / top. Make sure all your lines are tight as well.

    Even with no filter at all you should be good.

  6. I had replaced the filter, bolt gasket (small red ring), rubber gasket (between canister and lid). All were seated properly, and no leaks were observed. I did not touch the bottom bolt (left it as is), so that gasket would not have been replaced.

    When I put the old filter back in the canister, the system works fine (new gaskets were left on canister.)  This makes me think it is not an air leak in the system. Otherwise the old filter would be giving me the same problem.

    What are your thoughts?

  7. I would check and make sure you didn’t leave the old seals up in there. And that you have replaced all the seals and gaskets. Do that first and let me know ok.

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