Fuel Oil furnace in hard lockout 3 times in the last month

[JRP3]

Wondering what the possible causes are to make it go into hard lockout but startup fine when reset. Becket burner, Honeywell 7284 controller installed 2017, flame ohms around 200 when running, furnace was cleaned a few months ago. Bad flame sensor?

 

[bigealta]

Plugged oil line? i'd open the pump bleeder to confirm good oil stream and no bubbles. Quick and easy check to do.

 

[JRP3]

I'll check but I'd think if it were a fuel supply problem it would keep shutting off instead of running for weeks between lockouts.

 

[Bad LP]

I'll check but I'd think if it were a fuel supply problem it would keep shutting off instead of running for weeks between lockouts.

Check the oil pump for free movement.

 

[bigealta]

Yeah what did the "clean"? Did they replace the oil filter? assume yes there. But did they clean or replace screen on fuel pump? I've had that almost completely clogged. Burner would sporadically lockout before i replaced it.

 

[brenndatomu]

There is a whole myriad of possibilities on this one...very hard to online diagnose unless someone is HVAC and works on these things everyday...and even then it would be no slam dunk.

 

[mellow]

Had so many things replaced on my Beckett oil burner short of the gun itself. All the electronics,pump, sensors. Seems like something new every year. I have a long run to my oil tank outside so I tried installing a tigerloop a couple years ago and it worked good but all of a sudden it didn't work and had to go back to the old way of filter then going directly to the pump which was upgraded.

 

[bigealta]

This is what i'm talking about. Strainer. No need to remove pump though. Just do it in place if you decide this could be your problem. Good to replace this every few years anyway.

 

[bigealta]

Also

 

[gthomas785]

check:
oil flow
spahk
nozzle
electrode position

What is it doing before it locks out? Does it fire and turn off a bunch of times? Or does it try to fire and fail?
Any evidence of sooting or combustion issues since it was serviced?
Intermittent issues like this can be hard to pin down even for an experienced technician. You basically have to go through and check everything.
When mine was doing this it ended up being the transformer going bad.

 

[fbelec]

let it fire by itself a few times and listen as it cycles. if the fire is intermittent before it cycles off it's a blocked filter or maybe the hole inside the tank is partiality blocked by either the hole from the tank to the filter from wax maybe the sludge inside the tank is letting go and blocking or the filter is blocked again from sludge letting go. if none of that then it's time to put a fuel pressure gauge and watch that. that will tell you if it is time for fuel pump or line blockage. also put a vacuum gauge on the input and see if that is bouncing

 

[JRP3]

Since it's Mom's furnace and I didn't want to keep having to drive out there if there were more problems I called a pro. They replaced the nozzle and flame sensor. Hoping that fixes the issue.