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Our oil burning furnace needs repair

Started by Russell Kanning, February 17, 2007, 07:41 AM NHFT

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Russell Kanning

I was hoping one of our buddies on this forum could help us repair our oil burning furnace or recommend someone to us. We can pay in silver or $s and will not mention the transaction with the feds. :)

We have a normal Miller oil burner in our mobile home. The fuel is getting up to the Beckett unit, but it doesn't ignite. I am thinking it could just be a clogged nozzle since we have not swapped it out in more than a year.

On monday or tuesday I will call a local repair guy, if we can't find someone on this forum.

Lloyd Danforth

We got a guy,Maine Shark, but, he lives just east of where Margot lives.  I've seen my repair guy diagnose my old burner so many times, i know what to try, but, I could never explain it.  Basically, once they determine it is getting fuel, they make sure the fat square transformer (on top, hinged) is making a healthy spark and the tube thing that pulls out of the gun is clean.
If you get a guy in watch what he does.

Kat Kanning

He bled the air out.  We were thinking maybe the nozzle was clogged.

41mag

There should also be a filter in the fuel line somewhere.  It may need to be changed.

jaqeboy

You can buy new nozzles at hardware, plumbing or big box home stores. Actually, you can unclog it if you have fine enough wire to poke into the holes, but most people just replace them. Look for markings on the nozzle or just take it off and take it with you and get the counter guy to sell you a replacement (or 2 - keep a spare for when this happens again - they're not that expensive)

Kat Kanning

It doesn't appear to be an electrical problem.

Thanks for the suggestion Jack.

Russell Kanning

So it is not that hard and takes no special tools to replace the nozzle?

Jim Johnson

I can come up and touch it again tomorrow.
What time is good for you?

Russell Kanning

Quote from: Facilitator on February 17, 2007, 09:44 PM NHFT
I can come up and touch it again tomorrow.
What time is good for you?
Any time really :)
You will have to wear your wizard robe.

Russell Kanning

Jim brought his magic wands (both american and metric) and fixed it in minutes.

It was a plugged nozzle. Thanks for the ideas guys.

MaineShark

Quote from: wholetthedogin? on February 18, 2007, 06:32 AM NHFTMake sure the fuel petcock above the filter is turned off .  If it is completely open (counter clockwise) close by turning completely clockwise.  If it is only a half-turn deal ---turn it the half turn(which means its handle should cross the fuel line perpendicular).  Is it possible the fuel line was in the off position already.  If your filter needs replacing chances are that a new nozzle would clog up pretty quickly. 

The nozzle can be removed with an adjustable wrench.  If you have a 1/2" open end wrench or 13mm---hold the body of nozzle with one and disconnect fuel line.  Make sure you have a container to catch fuel under it and then gently turn the line upward.

Reconnect everything ---all copper fittings should be snug.


You will have to re-bleed.  Find a container to cover the spent fuel.

If you ever have to buy K-1 in an emergency fill remember to bleed the line.
Blue containers are for diesel/K-1.

Before you put your cover back on check the condition of the air filter and replace if necessary.


Pg.  13  Zen and the Art of Furnace Maintenance by Dawg

FYI, none of this is correct.

The shut-off valve will be a Firomatic valve, which has a wheel, and it is off when the wheel has been spun so far that it unscrews (and then tap the stem firmly to make sure it has seated), but there is no need to shut off the Firomatic in order to change the nozzle, as the fuel pump has an internal valve that closes when it is not spinning.

The ignitor is hinged at the back (closest to you) and secured by clips or screws at the front (closest to the furnace), which are typically 5/16" hex as well as slotted (a nut driver will work easier, but a standard screwdriver works in a pinch).  After the ignitor is swung open, use a 7/16" wrench to loosen the nozzle line from the drawer assembly.  The nozzle line is the thin copper line on the left of the burner, and the drawer assembly is the L-shaped piece of pipe (and associated components) that is inside the blast tube (the "business end" of the burner).  There will be a knurled nut or hex nut that holds the drawer assembly in place (on the same threads that the nozzle line connected to).  The assembly can be difficult to remove, particularly on Millers or other appliances with short blast tubes, but be patient.

After removing the drawer assembly, hold it over a bucket as some oil will leak out.  The nozzle can be removed with a 3/4" and 5/8" wrench.  The 3/4" wrench goes on the hex portion of the drawer assembly, and the 5/8" wrench goes on the nozzle.  Some burners (Carlin, in particular) have a fixed combustion head that has to be removed from the drawer assembly (typically, a single screw that just needs to be loosened) before this can be done.  Change the nozzle, being careful not to contaminate the new nozzle, as the orifice is about the size of a human hair (contrary to some opinions, nozzles cannot be cleaned, as the orifice is too small, and even if that could be cleaned, the internal passages are smaller, and are the more likely site of the blockage).

Now, that's only halfway to what you need done; the electrode position is absolutely critical to clean, safe, reliable operation.  There is no single adjustment on a burner that is more important than the electrodes.  Buy a Beckett "T" gauge, if you have to, but get a "Z" gauge if you can.  The Z gauge is simple - just slide it over the nozzle, and adjust the electrodes to sit at either side of the small "block" on the nozzle-end of the gauge.  If you have a Carlin burner, there are similar gauges for the Carlin electrodes.  In any case, don't use too much force, as you can break the porcelain insulators.

After re-inserting the drawer assembly, install the knurled nut and re-connect the nozzle line.  There is no need to bleed anything.  Close the ignitor and you're ready to run.

Of course, this is not a full cleaning, as would be performed by a competent technician.  That's simply replacement of the nozzle, and the barest minimum checking of settings.  A skilled tech would remove the burner and clean the head and combustion chamber, verify the Z dimension, replace the fuel filter and the fuel unit strainer, check the CAD cell eye, verify that all the safety controls are operating, check tightness and condition on any belts, inspect all valves and other system components, clean the heat exchanger, flue, air passages, etc.  And adjust the combustion settings with instruments (preferrably the newer electronic instruments, but the "shake and bake" manual kits work, too, if you're patient).  Among other things I'm sure I missed when typing this quickly.  A proper cleaning never takes less than an hour.  Cleaning a Miller generally takes two hours or more, because of the compactness of thost furnaces.

Oh, and K-1 generally goes in yellow containers...

Joe

Kat Kanning