Help with sludged ignitor

josephny

I just bought a small house with a Miller/Nordyne CMF2-80-PO-CONV furnace with Beckett AF-15 oil burner.

The unit was working fine for the first couple of weeks and then stopped.

I troubleshooted oil flow and then took out the nozzle/ignitor assembly and found the nozzle, and the tube that the nozzle screws on to, covered in oil sludge.

I didn't have a new nozzle, so I cleaned everything as best I could with acetone, reassembled and now it works.

One thing I discovered is that there is no filter on the oil line. Nor is there a shut off valve on the oil line.

The tank is outdoors and underground and copper tubing (feed and return) run from tank to furnace.

Am I correct that those things would be smart to put in?

If so, what is the best way to set it up?

Should I use hard brass NPT threaded pipe out of the furnace to support the filter case, then a nipple to a valve, and then back to tubing?

What I'd really like is a valve that has NPT on 1 side and flare for tubing on the other (I don't have much experience with flairing).

Am I correct in my usage of NPT and flair?

Lastly, the current nozzle is a 60-80 (which, I believe, means 0.60gph and 80 degree spread). Should I replace with the same spec or different?

Thank you very much!

SuperTech

Most mobile home oil furnaces are not equipped with an oil filter unfortunately.  The oil pump strainer is the only thing to protect the nozzle. I like to install a Tiger Loop Ultra on these furnaces.  It adds several benefits to keep the burner running right and the braided flexible oil lines make installation simple.  You will need to add a bypass plug into the oil pump. The Tiger Loop Ultra also includes a firomatic valve that can be used to shut off the oil to the burner, but a ball valve with flare connections is better for service use.

josephny

Wow, the Tiger Loop Ultra looks great. But now I'm wondering where I could fit any filter inside this cabinet.

SuperTech

I usually install them in the top left or right corner, above the burner.  On yours I would go with the left side near the power cord for the burner, more room there.

HVACNUT

Unfortunately there's no feasible way to do a combustion test on those furnaces without going on the roof, which I think is total BS. IMO, they should provide a test port.
The nozzle needed should be listed on the door. They might list 2 firing rates. The pump strainer should also be replaced, and if using kerosene, the cause of the sludge should be found. 
I've never had a sludge problem on a Miller firing kero without a filter. 

josephny

Wow, thank you guys so much for your help!

I will order a Tiger Loop Ultra.

Would anyone know exactly what to call the adapter from threaded valve (the one that comes with the Tiger) to copper flair?

Looks like Beckett has a complete bundle (Tiger Loop, valve, hoses, filter, mount) -- S220-12

Looks like I will need to cap off the current oil return line, right? Flair plug/cap?

josephny

HVACNUT said:

Unfortunately there's no feasible way to do a combustion test on those furnaces without going on the roof, which I think is total BS. IMO, they should provide a test port.
The nozzle needed should be listed on the door. They might list 2 firing rates. The pump strainer should also be replaced, and if using kerosene, the cause of the sludge should be found. 
I've never had a sludge problem on a Miller firing kero without a filter. 

I searched and scoured and I don't see a pump strainer on the unit or in parts diagrams.

I did find that the recommended nozzle is a 60-80A.

I haven't put any kerosene in the oil tank.

Are you suggesting that I don't need a filter?

Thank you.

SuperTech

Usually it's recommended to run kerosene on mobile home furnaces. It tends to be burn cleaner and is less prone to some of the issues that go with regular #2 fuel oil. However I have heard its a little more expensive.  You can cap off the return line if you go with the Tiger loop.  The strainer is a standard Suntec strainer for the A2VA-7116 oil pumps and Beckett clean cut pumps. I believe the adapter you are looking for is a 3/8" NPT x 3/8" flare adapter.  Sometimes I can clean up those pump strainers with a little carburetor or brake cleaner. If it's really sludged up just replace it.