Can't get a clean burn

mike117

Hi everyone I'm new to the forum and been in the trade for roughly 4 years now. I primarily work with natural gas and propane but do on occasion work on oil. I went to a no heat call where the company I work for had installed a roth tank. We do not know when the furnace had been running previously, but the guys who installed the tank said they fired the furnace and it ran for 30 mins before they left. Okay so I go in a couple days later to see whats going on (house is vacant).


furnace is a newmac LFR-2000 running a 0.50 45B nozzle in beckett burner

I had to push the nozzle assemble forward the z setting to get the furnace to fire, as soon as it lit looked through inspection smoke and sparks...coming out the draft regulator. I pulled the vent connector off and took a look to find a 3/4 plugged base of chimney...cleaned that out and used mirror up chimney to see an obstruction, climbed up and took the cap off and top 3 foot section ( manufactured chimney) the inside pipe was some how collapsed. I removed that section and put the cap back on to try and fire the unit again. Put a new nozzle in and fired the unit...smoke test...black adjust air ....smoke test black ....more air or less air still getting a dirty burn . I know its bad idea to use analyzer in a dirty burn but I wanted to get an ex air reading , couldn't even let the reading equal due to rising co levels. I've played with all the settings and the air restrictor plate is installed as per rating plate and nozzle size also have correct pump pressure of 180psig. The unit does remain running but I cannot get a safe and clean burn on the unit.

Any input is much appreciated! Thanks

STEVEusaPA

Put the Z dimension back to the proper number. That's giving you too much air (forward) and super high CO. You shouldn't have to adjust it just to get it to light. That tells me that you have other problems.
Put everything back to factory, including initial air settings, start over. 7.5 shutter, 0 band, -.02 draft over fire.
Otherwise you'll soot that thing shut in a day or 2.
How's your ignitor? How did you test it.

DanHolohan

Great advice, Steve. Thanks.

mike117

STEVEusaPA said:

Put the Z dimension back to the proper number. That's giving you too much air (forward) and super high CO. You shouldn't have to adjust it just to get it to light. That tells me that you have other problems.
Put everything back to factory, including initial air settings, start over. 7.5 shutter, 0 band, -.02 draft over fire.
Otherwise you'll soot that thing shut in a day or 2.
How's your ignitor? How did you test it.

Thanks for the input, should I put it back to where it was when I found it or take the burner off the furnace and use a beckett gauge to set it? As for the igniter I usually pull a flat head screwdriver across the terminals but didnt in this case because it seemed to ignite fine just wouldnt stay lit after a few seconds .

EBEBRATT-Ed

Pull the burner set the z dimension. Check pump pressure and nozzle clean and set the electrodes, clean the boiler and fix the flue
Then you can start it and combustion test

the_donut

Did they fill with fresh oil or empty old tank with sludge into new tank?

STEVEusaPA

Do you have an end cone, or a V1 or L1 head?
If there is an end cone you can use the Beckett Z gauge, otherwise you have to pull the burner. I wouldn't just put it back to where it was because you don't know if someone else moved it.
The first time I touch any burner, I check the Z dimension and outline the eschucheon plate with a black magic marker.

I'm confused about the following...First you state the burner was running poorly, now when asking about checking the igniter, you state the burner ignited, but only for a few seconds.

You mentioned a Roth tank, so the line is coming out the top. I'd also check the fuel line for a possible vacuum leak, or the line wasn't bled properly.

mike117

Fresh oil.

There is fuel from the tank as there is a tiger loop installed.

It was running for a few seconds only before I moved the burner assembly forward. The burner does not have a fixed end cone.

SuperTech

The burner doesn't have a fixed end cone? And it's a Beckett? Is it really old? Do you remember what model burner it was? AFG, NX, AFII? Pictures would be a great help.

mike117

Afg burner

rating plate
https://imgur.com/a/Ojtja

SuperTech

Sounds like the CO problem might be caused by flame impingement. Were you able to get a good look at the condition of the combustion chamber?

I've never heard of that make and model furnace and I see a lot of oil fired equipment in my area. The only time I see residential stuff without a flame retention burner is when it being ripped out for replacement.

The rating plate looks old. I'm not sure if you can believe that it was 100% ok before the tank was replaced.

HVACNUT

> @STEVEusaPA said:

> You mentioned a Roth tank, so the line is coming out the top. I'd also check the fuel line for a possible vacuum leak, or the line wasn't bled properly.

And Roth recommends a Tiger Loop in the install manual.
Especially if the line(s) is going up, over and down.

STEVEusaPA

HVACNUT said:

> @STEVEusaPA said:



> You mentioned a Roth tank, so the line is coming out the top. I'd also check the fuel line for a possible vacuum leak, or the line wasn't bled properly.



And Roth recommends a Tiger Loop in the install manual.

Especially if the line(s) is going up, over and down.

My comments were made before the OP mentioned a Tiger Loop.
I only see an oil deaerator offered as an option, not a recommendation in the instructions. Do you have different instructions?

Big Ed_4

Funny they want the Beckett firing an 45* and the Riello 80*