Oil burner is resetting intermittently. No DHW. Plumber just cancelled last minute.

ThatF_inGuyInNY

Hi all,

I have an oil fired boiler that feeds an indirect water heater. Yesterday, the burner cut off. This has happened once or twice over the years. I typically just hit the reset button, it turns back on, and good to go. This time, it just shuts right back off, so I know theres an actual problem.

Theres plenty of oil, so I know thats not it. The burner is a Beckett RWB. The boiler does light when I reset it, it stays lit for a maybe 10 seconds then resets.

A local boiler company was supposed to come out today, but they just cancelled on me and cant come until tuesday. That doesnt work for us. My wife starts a new job on monday and shes already stressed.

I have pretty extensive non-professional experience with plumbing and electrical, so Im not afraid to get my hands dirty. I tried to do the right thing here and bring in a pro to work on the burner, but thats not worked out so Im reaching out here thinking that if it is a minor issue with a simple fix, I can get it done.

Do these burners have any kind of diagnostic info, like error codes? Im thinking probably not, but worth asking (the red indicator light is on).

Other than that, are there any other obvious and simple solutions here? Possibly the oil filter is clogged? Like I said it does actually light, so that makes me think its an oil feeding problem.

ThatF_inGuyInNY

Ok, so I possibly made some progress is diagnosing. I opened the burner and cleaned the CAD cell. It wasnt particularly dirty but had a small bit of caked up dust on it. Then I fired it back up. The burner lit, but this time, after about 20 seconds, the flame stared going on and off then eventually burnt out. Expectedly, A bit of soot wafted out of of the boiler as the flame went on and off. I did hear a faint scraping sound coming from the burner as the flame went in and out.

Dave Carpentier

When was the filter last changed ? Could the scraping sound be the pump running dry of oil ?
Cheap enough fix/test to swap a new filter.
Can also pop the cad cell off and test resistance to check if its getting tired.

HVACNUT

Did you keep the Tuesday appointment and/or try another oil service company? It's not DIY and a cold shower never hurt anyone. Its actually a good water cooler story for a first day on the job. 
When was the last time it was serviced? 
Whoever does the work, ask for combustion, draft, and smoke tests. 

EBEBRATT-Ed

Sounds like the oil filter is plugged' It could also be the nozzle plugged or the strainer inside the pump.

You can go at it yourself but it's really a job for a burner tech

EdTheHeaterMan

My first test would be to place a pressure gauge on the high pressure line. This will tell you several things. By disconnecting the high pressure line and plugging it with a gauge, after pressing the reset button, you will see if the pressure is set properly, if there is no oil pressure, or if the pressure jumps up slowly or if the gauge flutters back and forth (usually on a 2 pipe system) there is a blockage in the fuel line or fuel filter. After 15 or 45 seconds the burner motor will stop. Several tests in one short procedure. (I also test the ignition in this step too, but since the flame is lighting according to the OP, that is not necessary on this troubleshoot)

Since @ThatF_inGuyInNY probably does not have a gauge set up for the high pressure 3/16 flare fitting, I would tell him to remove the high pressure line from the bulkhead fitting on the burner and direct it into a container and watch the oil flow. The container should be at least a 1/2 gallon or a 2 liter bottle to allow for the 45 second safety timing. You can just put that oil back in the tank.

If the fuel flow is strong and constant, and does not spirt on and off with lots of air space between the spirts, that would indicate the problem is not the fuel system. If it does spirt on and off for the 15 to 45 seconds, then the fuel system is the problem. @EBEBRATT-Ed and @Dave Carpentier are on the right page with the plugged oil filter. This is a procedure you can do to test the plugged filter theory. Be careful when reconnecting the 3/16 flare fitting back on the the burner. It does not need to be overtightened. Snug then 1/4 turn past snug. if it leaks then add a little more torque til the drip stops. (use a 7/16" open end wrench or a small adjustable... but what ever you do... don't use pliers.)

If there is a plugged nozzle or other combustion issue, I would recommend a pro because you can really mess things up with air/fuel adjustment that require more experience than we can handle on a forum like this. Checking fuel flow and replacing an oil filter usually does not require combustion testing. If you do find that replacing the oil filter does the trick, it is very important to schedule proper maintenance by a qualified oil heat technician ASAP after your temporary fix.

Hope this helps.

Mr.Ed

rick in Alaska

Personally I am leaning more to a bad fuel pump coupler.
Pull the motor off the right side and pull the plastic coupler out that connects the burner motor to the fuel pump. Make sure both ends stay with the coupler. Then hold both ends of the coupler and twist it and see if you can turn it. If it does twist inside, then it is stripped and needs to be replaced. If it doesn't twist, then inspect the inside of the ends and make sure the flat part inside is not stripped out. It should be round in the hole with a flat spot on it. Again, if it is stripped out, replace it. You might have to buy a kit and cut it to fit, so if you do, when you are done and reassembled, turn the fan by hand and make sure it is not too tight.
This is all assuming you are not out of fuel
Rick

ThatF_inGuyInNY

Hey guys. Checking in. I appreciate all of the help and suggestions. It actually turned out to be a simple problem that I am not sure how it happened. My oil valve was about 80% closed. I dont recall ever touching the thing as long as Ive been here. I opened at all the way up, the burner fired up and came all the way up to temp. It must've been open just enough to keep it running all these years, then maybe a little buildup or whatever caused it to choke off the flow.

Anyway, Im thrilled that the company cancelled on me. Paying them $150 to turn a valve would've crushed me.

Solid_Fuel_Man

Good find! 

Honestly, it amazes me that more oil techs done use spin-on filters and a perminatly installed vacuum gauge on the adapter. Can tell a lot. 

Here that is what we do in commercial settings, but I have done it on some of my residential installs. General filter, then the spin-on. 

Oil can be of dubious quality once an awhile. 

ThatF_inGuyInNY

Solid_Fuel_Man said:

Good find! 

Honestly, it amazes me that more oil techs done use spin-on filters and a perminatly installed vacuum gauge on the adapter. Can tell a lot. 

Here that is what we do in commercial settings, but I have done it on some of my residential installs. General filter, then the spin-on. 

Oil can be of dubious quality once an awhile. 

Is this an available option for resi boiler installs? My boiler needs to be replaced and I would consider installing this type of system.

EdTheHeaterMan

Here is what he is talking about:
https://www.supplyhouse.com/Gar-Ber-1603-11BV-RK-Gar-Ber-Spin-On-Fuel-Oil-Filter



But I prefer this set up. you can actually see the oil!
https://www.supplyhouse.com/Westwood-Products-S220-8-Tigerloop-Ultra-Oil-De-aerator-and-Spin-On-Filter-Model-TJN-UL-Listed

Jon_blaney

I am skeptical about the valve being part closed. It is it a firematic? They can fail. Maybe a replacement is in order.

EBEBRATT-Ed

Some probably serviced it at one time changed the filter bled it and forgot to open the valve all the way