Burner issues - wont re-fire

Nedly

I have been working on this burner and cannot figure out this issue. It fires up and runs fine for a good 15 mins, then it shuts down and will not fire until hours later even if it is powered off and back on. It is a Beckett model burner system with a basic 45 second intermittent igniter.

Parts replaced:
Main controlboard
Intermittent igniter board
Nozzle
CAD sensor
Ignition box
Oil filter / fuel check / line replacement

The thermostat has been jumped and that is not the issue. So I tested the L1/L2 and B1/B2 terminals in the aquastat and got a full 120vac reading on the B1/B2 but got a reading of zero on the L1/L2 terminals pointing to a low water cut off issue. But then others suggest that if the B1/B2 terminals have power and it is not running then it is the blower motor?

This is where I am lost. I have checked the intermittent igniter to check and see if it was kicking out or going into the safe lock out mode, but it seems that after the unit finishes the cycle and then does not start that it is in call for heat but it just sits there dead. I imagine it is either the water sensor / low water shut off system, or the blower motor. But if the blower motor were bad would it run the first initial cycle?

Anyones help with this would be great as I have replaced a lot and have been working on it almost a year now..

Thanks.

billtwocase

Pics will help in this mystery. You speak of a blower? Is this a forced hot water with an air handler? Kick space heater? The LWCO should be wired between B-1 preferably. What main control board did you replace? #'s?????

icesailor

Any possibility that there is a drop of solder anywhere near the two "F-F" terminals? If the burner stops while the "T-T" terminals are shorted, the burner will not re-start until the false connection is broken.

But, what is this "Board" that you replaced?

Nedly

I will get back to you with more info. It is forced hot water but we do not use that part to heat our house we use wood, so in this case we only run the burner to heat water for hot showers / dishes etc...

We got a basic Honeywell intermittent ingniter, and I know the main control board is a fancy one as it is set up to work with hot tubs and other things like that.

We had it functioning a while ago, one day it started acting up and we have not gotten it to work right since. Lately re drained the low water cut off setup and cleaned / checked the sensor and it made no difference. As far as those L1/L2 terminals, nothing seemed shorted out. I will double check just in case.

We have our doubts that it is the low water cut off, but who knows. I got a read of 0 on the L1/L2. It was not running when I tested it, it was only powered on. Should I run and test those terminals during its cycle?

This is the control system we got.. http://www.amazon.com/Honeywell-R81...r=8-4&keywords=honeywell ignitor intermittent
unit2.JPG

This is the one I am thinking about getting.. http://www.amazon.com/Honeywell-R81...keywords=honeywell ignitor oil burner control
unit2.jpeg

Though, I do have my doubts that it is the intermittent igniter as we have replaced and tried like three different ones. The main system is a Beckett AFG model...

Nedly

This is our main blower system.. http://www.beckettcorp.com/protect/manuals/6104BAFG.pdf

icesailor

That makes you a parts changer.

First, check the spark for strength. Then, the nozzle for it being the proper one for that application. Then, change the filters. Replace to spin-ons if not already. Check to see if there is a carbon buildup in the retention ring on the inside hole. If it is a draft problem, it can be insurmountable.

Change to Carlin or Riello.

My solution to a finicky and problematic Beckett was a nice running Carlin. Or Riello.

Nedly

Well, I did read about the intermittent igniters being defective. We drained the low water cut off and shut off the water supply, tried to start it and it did not run indicating the low water cut off is fine.

So, we noticed if we adjusted the high temp setting in the aquastat that the burner would heat right up to that temp, turn off, then not refire.

So it has something to do with the temp sensor? Or,..? Some mentioned the forced hot water aspect. It is set up to do forced hot water but we shut off that flow, we just use it for a water heater instead of an electric heater..

On your intermittent igniter opinions, we have considered the same thing, but we did replace this one three times and had the same outcome with each one, so it is hard to tell without knowing how to thoroughly test the intermittent igniter.

I got more model numbers and am working on gathering all the info to post.

Nedly

Everything you suggested above has been done except testing the strength of the spark (it does start initially fine), and / or replace the entire unit, which may end up happening if I cannot figure this out soon. I spent half the price a new unit would cost thus far on parts..

Nedly

Ok, so I am starting to understand this all a little bit better. One question, are the fazes of high limit and low limit where the furnace heats up to temp (high limit first faze), then the low limit is the water heating process (low limit second faze)???

That is exactly what it is doing!! It is running through the high limit cycle but then not moving on to the low limit cycle. What does this mean? This is what someone else mentioned but I am still trying to make sense of it..

" jumping the thermostat isn't how to make hot water, its the low limit in the controls that decides when it turns on from the aquastat in the domestic coil. If you are not using it for heating the boiler could be hitting its high limit and not turning back on at the low limit, with no low limit set int the controls. "

I have more news too. I guess the setup is that the forced hot water was never shut off, rather the "house" based thermostat has been turned all the way down so it does not call for heat. So should I turn that up and shut off the feeds in the line?

Nedly

So there is two thermostats? We have one jumped and the other turned down.

Nedly

Ok. So that makes sense, but what is the issue then? Or what could the issue be? What do you mean by " If the boiler is too large for the radiation (which it is)"?

Nedly

I am reading now something about an internal coil and an external coil? I do not know how this is set up, I am just now learning about the different coils, second thermostat, and the high / low limit process. So I understand where it is now, but what should I do to get hot water to the tap system and not the forced hot water system?

icesailor

Its nice to see a non-professional homeowner giving out unsubtstantiatable advice here

RobG

Now Ice, that's not fair. BC can do psychic heat loss's. Let me see you try that!

RobG

bc3510 said:

I struggled with an intermittent ignition failure for nearly one year on the Beckett as well.

Every week or so, it would trip on safety. Sometimes would restart with a reset...........sometimes would not.

Took me down the wrong path of believing air was in the lines as it would start after bleeding.

Changed the pump.

Same problem.

Changed the primary.

Same problem.


Finally checked the transformer for spark when it would not fire after reset.

Bingo.

Intermittent transformer. Replaced.

Has not tripped in a month.

Thank god your a mechanical engineer, you keep wholesalers in business.

icesailor

RobG said:

Now Ice, that's not fair. BC can do psychic heat loss's. Let me see you try that!

I do mine with a 16' inch/metric tape and some old IBR modern method work sheets. Or the Slant-Fin one. Same program.

icesailor

bc3510 said:

It's even nicer when a retired mechanic chooses to disparage a mechanical engineer when he has nothing to contribute and doesn't wish to assist the OP.

I stand by every statement made.

No one is perfect, Not even you.

And I never said I was.

I once saw a plan, with a ME's stamp on it that had a glaring mistake. It took a lowly peon, a graduate of a public high school to find it, but I did. I saw another small drawing where the mistake was drawn correctly. After the installation.

billtwocase

Still waiting for more info and pics from OP. His links were dead

KC_Jones

"Many of them are incompetent at the design and are basically glorified draftsmen."
lol I am a Draftsman/Designer and I agree with that statement...sometimes I wonder why they have their position instead of me since I am doing their work. Of course there is also the other side...the ones that are amazing. Those I am in awe of.

Jamie Hall

Wouldn't it be fairest to say that there are really good people in most trades and professions? And mediocre people? And, frankly incompetent people? Certainly this has been my experience...

[full disclosure here, for those who want to take pot shots -- while I am now best described as a building superintendent, I am also a fully registered Professional Engineer (Civil, Sanitary and Agricultural), and have been responsible for multi-million dollar projects as the Engineer of Record -- which, if nothing else, makes me liable for the whole banana if something goes wrong]

icesailor

The smart ones always know when to ask for help. And take it.

And knowing that who you ask isn't as Important as when and how you ask. Everyone has something to add to the answer. Most of them a=have no idea that they can help with an answer.

RobG

Ahhh, another thread successfully hijacked.

Nedly

Lol.... I am a full time college student prepping for a winter in Maine, so I have had to run around like a mad man lately.

So, I have pictures but they do not show the wiring very well. I replaced the aquastat and tested it, no fix. Replaced the low water cut off, no fix. So I did some more testing and found I think it is not the high limit shutting the system down but something else, and the box may be overheating to 200+ degrees...

Basically I played with the high limit switch on the aquastat and noticed the system runs beyond that to some higher heat and finally stops. I don't know what stops it or why it is overheating...

Nedly

To add to earlier comments, I am a CIS major and am far from incompetent. I have not worked on these furnaces much at all in the past. I have been watching videos on exactly how they function but cannot seem to trace down the issue in this one...

Nedly

Pictures. Let me know if there is more needed... Thank you for your help too..

billtwocase

A quick 3 things I see. One is that the cad cell relay is off on saety. two the serviceman's switch is off, and three your limits are not set right. I can't tell how that system/Boilermate is zoned. To start, set your LO at 180, Hi at 200, Diff at 10. Have you pushed that reset button previously? If so, best to have it looked at. That is a bad control. It can be a serviceman's worst nightmare.

billtwocase

Another tip. Situations like this are not always best researched on Youtube. I see a lot of vids that take you in the wrong direction. There is a line that has to be drawn

icesailor

That's a bomb/idiot proof boiler and burner.

Your futzing around have turned it into a nightmare. First being that you have the controller set too high. The "LO" should be set to 140 degrees and the "HI" set to 170 degrees. Leave the "Diff" alone.

Nedly

I will make those adjustments. The knobs have not been turned up that high all the time I was just experimenting at one point.

So if I make adjustments to the temps and the system does the same thing, what next?

Nedly

billtwocase said:

Have you pushed that reset button previously? If so, best to have it looked at. That is a bad control. It can be a serviceman's worst nightmare.

Which reset are you mentioning to?

RWTarpey

Nedly,
1- Make sure the relief on the boiler works.
2- Make sure you have water in the boiler and not air. You mentioned you drained it down to check low water cut off.
3- If you are operating the boiler for only domestic hot water, you need to make sure the ciculator for that zone is moving water to the boiler.
4- lower the set points on the aquastat.
5- If you haven't had to press the reset on the burner and the burner will cycle back on if given enough time, then most likely the problem is not with the burner but a control or wiring.
6- It also looks like theres a new oil line?

icesailor

I just read back to the beginning:

"" I have been working on this burner and cannot figure out this issue. It fires up and runs fine for a good 15 mins, then it shuts down and will not fire until hours later even if it is powered off and back on. It is a Beckett model burner system with a basic 45 second intermittent igniter. ""

If you have that "LO" set as high as you have it in the photos, the circulator may never run. The boiler is off on high limit I assume. The burner won't run until the boiler cools down enough for it to run.

If you've been playing with this thing for a year, and changed hundreds of dollars worth of parts, you've crossed something up. Like I said before, that boiler/burner combination is as close to being bomb proof as you can get. Like a 1970's kids bile with the banana seat compared to my Hybrid Mountain Bike with all the gears.

Nedly

Yes installed new line with theories that the original was causing issue with moisture. Before these issues became consistent they were intermittent, as it seemed we could get it to work here and there, or sometimes it would take a few tries to get hot water. So we originally thought the CAD sensor and a few other parts like filters, nozzle, eventually the line, then later the igniter components and water cut off system..

I am going to work on all of that and I will get back to you.

Nedly

billtwocase said:

One is that the cad cell relay is off on saety. two the serviceman's switch is off,

Where are these buttons that you see? I cannot find them on the aquastat, should I switch them on?

And I cannot find anything regarding a circular pump in the manual..

billtwocase

Nedly, the switch labeled "emergency switch" in red above the blue relay box should be in the up position. The red reset button is on the burner cad cell relay. It has a trip switch next to it. Perhaps you hit it by accident? You can press it once only. If it reacts, and shuts down in less than a minute, do not press it again.

Nedly

Everytime we have worked on it we have replaced a part as it was, outside of what was listed nothing has really been done. That is where a lot of my confusion comes from is because it did work under its current design once upon a time. Everything has always been put in the way it was..

Nedly

billtwocase said:

The red reset button is on the burner cad cell relay. It has a trip switch next to it. Perhaps you hit it by accident? You can press it once only. If it reacts, and shuts down in less than a minute, do not press it again.

If this had been hit what is the solution to have it functional again? Does it make the unit obsolete?

Nedly

That box with the reset and switch is one that has been replaced several times and I do not think it has been hit but I cannot be positive..

This was my first big lead and I am still suspicious at times because many people online reported buying them defective. We have tried about three now, and one of the ones we purchased had been opened so it could have been a return as well...

icesailor

Many people on line haven't a clue what they are taking about when they tell you that "many of that control is defective". There is a check-out procedure. It is simple. You need a paid experienced professional. Not some rookie dubber who gives the rest of we oil and heating professionals a bad name.

I'm telling you. What you have is as bomb proof as you can get. They could use that boiler/burner set up in Voke schools to teach oil burner service and repair.

Some can say I don't know what I am talking about.

Nedly

I tried it again with the limits low, checking the circulators. Circulators power on and seem to be working, and no matter how low the limits are it will burn 200+ if I let it, eventually overheating and shutting down...

Nedly

Could it be the blower motor? Possibly not giving enough oxygen?