Flame rollout switch - keeps going out

EdTheHeaterMan

ChrisJ said:

Here's my issue with it and @JohnNY please correct me if I'm wrong.  I'm not a pro but I am concerned about those in that building.

I see comments about exhaust hoods and draft....
My understanding is a draft hood equipped boiler should burn properly without any draft at all.  It's part of the draft hoods job.  There should be no soot and no roll out with a completely blocked flue or even a down draft.  


The burner doesn't rely on draft from the chimney.

At least that's my understanding of how an atmospheric draft hood equipped appliance should operate.

Its also my understanding that NG and LPG do not produce soot unless something is really really wrong.

Please get that addressed NOW.

Ok, let's look at the situation from the perspective of a person who cleaned oil boilers for a living.
On one occasion a homeowner finishing a basement and enclosing the boiler room. This causes carbon to clog the boiler. There was back pressure enough to discolor the burner jacket to discolor it just above the sight port door.
On another occasion, a customer installed a Whole House Fan instead of Air Conditioning. When the oil burner operated for hot water and the fan was operated to cool the house, the burner also made carbon build up on the heat exchanger.
On another occasion, the air-fuel mixture was set incorrectly and carbon built up enough to plug the boiler as pictured above in a previous comment, many times.

In all three of these occasions along with many, many more over my 40+ years of oil burner and gas burner service, I have vacuum cleaned the soot and used a soft brush to get the boiler clean. Once the flue passages in the heat exchanger were clear, I would determine the reason for the incomplete combustion and make the necessary repairs, adjustments, or correct the insufficient combustion air issue and recommission the boiler. The scorch marks would be there for many years after the problem was resolved with no further combustion problems.

Now I ask all you experts about a boiler with this soot condition, If your car had a dirty windshield blocked with snow, dirt, or even some carbon, would you replace the car, The windshield or would you get some Windex?

JohnNY said:

ChrisJ said:

Here's my issue with it and @JohnNY please correct me if I'm wrong

You're not wrong, @ChrisJ. I didn't read through the prior 39 posts here but there can't have been that much to say about this boiler. It takes a lot to activate a flame roll-out switch and when I see scorch marks over a burner tray, I know the boiler has been operating in an unsafe condition for a significant amount of time, and its problem is within the boiler jacket.

This boiler has to go in the garbage and if someone has to be held accountable for its failure that's secondary to the problem.

After you replace the boiler (without removing the whole house fan) and the new boiler soots up again, What will you recommend next? @JohnNY

I think you will try to find the cause of the issue and later find the Whole House Fan that was not operating in October when you installed the new boiler.

(I know this from experience. In 1983 I serviced a gas boiler that sooted up and I cleaned it 2 times before replacing it. When the new boiler also sooted up the following summer 10 months later, I put on my Sherlock Holmes hat and found the fan in the ceiling on the second floor)

It is ok to clean the boiler and recommissions it. As long as you find and eliminate the cause.

Merry Christmas
Ed

EdTheHeaterMan

ChrisJ said:

Here's my issue with it and @JohnNY please correct me if I'm wrong.  I'm not a pro but I am concerned about those in that building.

I see comments about exhaust hoods and draft....
My understanding is a draft hood equipped boiler should burn properly without any draft at all
This is not correct. the draft hood on a boiler is to allow dilution air into the flue gasses to keep the flue gas from condensing at the lower temperature at the top of the chimney.

.  Its part of the draft hoods job.  There should be no soot and no roll out with a completely blocked flue or even a down draft.  


The burner doesn't rely on draft from the chimney.

At least that's my understanding of how an atmospheric draft hood equipped appliance should operate.

Its also my understanding that NG and LPG do not produce soot unless something is really really wrong.

Please get that addressed NOW.

You can have a gas flame in a burner designed to use the atmospheric air pressure around the gas orifice/burner to burn off the burner by forcing air excess air over it. the way a high chimney draft might suck the pilot off the pilot burner. OR it could burn properly with the correct amount of air (which is an extremely large range given they work at sea level, and at mountain high regions. OR you can reduce the oxygen from the air by adding more nitrogen and watch the flame get rich and burn yellow with lots of smoky tips. So atmospheric burners have the same needs as any other burner.

Now consider this... you get insufficient oxygen in a burn and a small amount of the soot sticks to the heat exchanger. No one notices it today. You have that same condition a week later and you get a little more build-up. Again not enough to notice. Over several months the blockage becomes more and more until the passage-ways are 70% blocked. Still, no one notices The byproducts of combustion now containing anywhere from 7% to 15% oxygen recirculate back into the combustion air.

OK... now you have combustion air with less than the normal 20% to 21% oxygen. This combustion can't burn clean even if you have twice as much air as you normally need. Recirculation of flue gasses will build up soot in a matter of a few hours if left unattended. (I know from experience after cleaning a burner and forgetting to lock the combustion air setting on a burner. Went back to clean the boiler at night for free. Never made that mistake again)

So just clean the boiler and recommission it after finding the reason for the incomplete combustion.

My vote is for @JUGHNE's comment "As suspected.....would the demo crew have run a powerful exhaust fan out a window during plaster removal and had the boiler firing for heat?"


Just My Thoughts

EdTheHeaterMan

@foresthillsjd Just have the cleaning completed as you did and keep a vigilant monitoring program in place. Now that the burners are clean and the flue passages are clear, and you are not going to rip all the new sheetrock off the walls and you provide a larger opening to outdoor. You will be just fine

If the steam boiler is the only gas-burning appliance in the room then you need two openings to the outdoors with a total free area of 50 square inches. One at the top of the room and one at the bottom of the room. If the bottom of the room is below grade you can add a vent from the opening to a location within 12" of the floor.

So you might be looking at 2 louver openings of about 10" x 10" each. And you only have one opening.

Your professional service person should be familiar with the minimum requirements. Here are some illustrations of different minimum requirements. There is one for using only one opening, but the BTU/Sq" of free air is different

HomerJSmith

I posted this on page 1 and didn't see page 2 which pretty much covers the issue. Thanks Ed!

Wow! Who ever said that a reservoir boiler doesn't need to be cleaned.

I am of the opinion that the soot buildup on the HX is a result of incomplete combustion, not so much drywall dust. I would be concerned with combustion air as the combustion is on the wrong side of the curve. Either too much gas or not enough air.

The burner flame never looked right.

But, I don't see lift off of the flame on the burner tubes in the video, but the gas delivery need to be checked to make sure.

When I clean burner tubes, I pass an inspection camera up the HX.

HomerJSmith

foresthillsjd, I don't know what elevation above sea level you are at, but maybe hills is a hint.

Boilers above 2500 ft need to be derated which means on your type of boiler a change in the boiler orifices to a smaller size hole to balance the air fuel ratio for near complete combustion. Not compensating for the reduced oxygen content of the air gives one a rich gas mixture and an increased carbon buildup.

I live in the mountains and I find that most plumbers just install the boiler without regard to the elevation and these burner orifices never get changed.

Checking input pressure to the gas valve and the manifold pressure during combustion is what I mean by gas delivery and should be a part of your servicing.

ethicalpaul

Not a bad idea, Homer, but it's in Queens, NY. Elevation 100 feet

HomerJSmith

I don't know much about NY except that my daughter went to Cornell School of Engineering. The only thing I knew was every semester my bank account went down.

SteamingatMohawk

Low tide or high tide?

deyrup

Are old homes ventilated by purposely being leaky then? I looked in my two family home basement and I don't see any purposefully installed ventilation besides dryer vents and a chimney. In my 1200 sq ft mostly open basement I have listed max btu usage of:
Burnham steam boiler: 105k btu
Tank water heater: 40k btu
Navian tankless: 150k btu
Burnham steam boiler: 140k btu

Which means max usage of 435 btu/hr, and I should have a 21" x 21" opening?

pecmsg

deyrup said:

Are old homes ventilated by purposely being leaky then? I looked in my two family home basement and I don't see any purposefully installed ventilation besides dryer vents and a chimney. In my 1200 sq ft mostly open basement I have listed max btu usage of: Burnham steam burner: 105k btu Tank water heater: 40k btu Navian tankless: 150k btu Burnham steam burner: 140k btu Which means max usage of 435 btu/hr, and I should have a 21" x 21" opening?

And that crosses over to a 7+” opening per minute 

Jamie Hall

Older structures were leaky. Not necessarily on purpose, mind you, but leaky they were -- and are. Furthermore, you want leaky. You may want to control it (say with HRV units), but you want leaky. I don't know what the current orthodoxy is on that, but years ago when I was helping my father-in-law on the design of passive solar houses, we came to the conclusion that 2 to 4 air changes per hour were the minimum required to maintain decent indoor air quality. It is not uncommon for newer houses to be tighter than that -- with predictably poor indoor air quality.

HVACNUT

Jamie Hall said:

Older structures were leaky. Not necessarily on purpose, mind you, but leaky they were -- and are. Furthermore, you want leaky. You may want to control it (say with HRV units), but you want leaky. I don't know what the current orthodoxy is on that, but years ago when I was helping my father-in-law on the design of passive solar houses, we came to the conclusion that 2 to 4 air changes per hour were the minimum required to maintain decent indoor air quality. It is not uncommon for newer houses to be tighter than that -- with predictably poor indoor air quality.

That's about it Jamie. A HERS rated house wants about 3 air changes per hour.

Alan (California Radiant) Forbes

We see that often on atmospheric hot water boilers serving radiant heating without boiler protection. There are a lot of Laars boilers here and it's a common symptom.

I usually remove the burners and hose it down with multiple strong sprays of water and have a wet/dry shop vac suck it up from below at the same time.

foresthillsjd

Here is a picture of the current flame.  I will get a combustion test as soon as I can find a guy who has availability.  

There is a CO detector in the boiler room.

The only other thing I can think of that might have added to the problem, and I don’t know if this matters, is that when we bought the house, about half of the burner tubes were installed sideways.  I didn’t realize it and fix it until we fired on the boiler this year. 

I am hoping this thing will last me this season, then in the spring I will open it up again and see if soot has built up.  I had considered hosing this thing down when we were cleaning it, but we don’t have a floor drain.  I need to find a wet vac before going down that road.  

I am also going to start cranking the window open when I operate the dryer.  I have been in NYC apartments way too long, where they use a lot of electric condensing dryers.  It never occurred to me that gas dryers vented to the outside were essentially giant fans, so thanks for educating me about that.  

HomerJSmith

Looks good, but how about a video of the light off, like your first one. I would be interested in seeing it.

Something that just occurred to me is grounding the burners to the ground on the gas valve. hmmm.

foresthillsjd

The plot thickens... so last month, I had a McDonnell & Miller 67M low water cutoff added to the boiler (something about code needing it even though there is an automatic water feeder too). After two days of things running okay, my thermostat is giving me a "no power" message. So I go down, everything is fine (checked for continuity on rollout and spill switches, water level good, pilot fine), and I push the reset button on the cutoff, everything powers up, and all is fine. It runs for a couple hours, then the same thing happens.

Do I have a second problem unrelated to my first problem?

HomerJSmith

"The plot thickens..." I like it, like Agatha Christie Mysteries.

Send a picture of the 67M and its location and wiring if possible.

HVACNUT

The manual is in a lower tap than the auto?
Is there any surging?

motoguy128

foresthillsjd said:

@EBEBRATT-Ed I had the chimney relined two years ago. It's 7" smoke pipes that get reduced to 35' of 6" stainless steel liner.
Should be sufficient, right?

Even though its a tall 35’ chimney, they still shouldn’t have reduced it to 6”. Could be compounding the problem.

EBEBRATT-Ed

@motoguy128

It is common to have a liner smaller than the boiler connection with a tall chimney

JUGHNE

Burners installed sideways would certainly could have produced some wacky burning. Maybe it was the cause of the sooting.

EdTheHeaterMan

foresthillsjd said:

The plot thickens... so last month, I had a McDonnell & Miller 67M low water cutoff added to the boiler (something about code needing it even though there is an automatic water feeder too). After two days of things running okay, my thermostat is giving me a "no power" message. So I go down, everything is fine (checked for continuity on rollout and spill switches, water level good, pilot fine), and I push the reset button on the cutoff, everything powers up, and all is fine. It runs for a couple hours, then the same thing happens.

Do I have a second problem unrelated to my first problem?

You bet your UYK you do! ??? I thought I typed YES ???

The new 67M has a manual reset. if your original LWCO is not detecting the low water condition and the second LWCO needs to operate, you want to know that before there is a more severe problem. If the water in the boiler is "Surging" then you need to address that with skimming, If the primary LWCO is not detecting low water properly then you need to clean or replace the probe (on the electronic type) or see why the float on the original LWCO is not operating before the new 67M LWCO.

neilc

time to show the controls on that boiler,
maybe one big picture, floor to ceiling,

neilc

and, , ,
what pressure do you see on your gage while its firing and been running a bit?
what pressure are you set to?
has the pigtail been serviced ?

EBEBRATT-Ed

@betweentheframe

Working on your own equipment is one thing. If you screw up it's your screw up and your problem and if someone dies it's your family your responsibility

Contractors have liability. If they screw up their killing someone else's family so many err on the side of caution and because I have a pocket full of licenses I fully respect that and understand that.

I like to fix thing too but there is a fine line between fixing and tossing and that line differs in different locations everyone has a different viewpoint.

Cost of labor is a big variable. If i am working on my own stuff my time is free and and I can do as much or as little as I want.

In some parts of the country New York City would be a good example labor is very expensive and spending a lot of time fixing something you will be liable for when you walk out the door may not be worth it

Just my opinion

foresthillsjd

thanks everyone for chiming in.  I haven’t gotten so many requests for pictures since my online dating days!!

the new 67M LWCO is definitely not shutting off on low water, and I have drained the boiler when cold to test that the auto feeder is kicking in when needed.  

The old Lwco that signals the auto feeder is a McDonnell Miller PS-802-24.  

I don’t know what the proper fill level should be on this thing, since there is no line on the jacket.

also, the instructions for the 67M say it needs its own transformer, but in my installation, it’s getting power from the same 24 supply as the boiler.  I don’t know if it matters.  

Also, I just cleaned out the pigtail for good measure.  It had a little sediment, but it wasn’t restricted.  

foresthillsjd

So update, I ran the boiler for 15 minutes, and it shut off.  The pressure didn’t get to anything meaningful.  (I ran upstairs while it was at zero, and when i came back a minute later, it was off.  The boilers on the first floor are hot though. When the boiler is not firing, it is filled to half of the sight glass line.  

neilc

did the boiler shut off at the thermostat, or cycle off by pressure?
OR,
did you have to reset that LWCO again?

previously I think you said you had to reset the LWCO,
the most recent post said "the new 67M LWCO is definitely not shutting off on low water",
which?

the white wheel inside the Ptrol should get set to 1,
the scale on the front might get dialed down just a bit more,
any extra pressure the boiler is making is pushing water into the returns,

the sightglass looks a bit dirty, like scum on top of water dirty, the skim port is still a factory plug, Sooo , , ,

danitheplumber

Was there any corrosion on the block? I see corrosion on the side. It may be worth spending the money on a new boiler rather then trying to rebuild old one just to find it rot out a year later. 

AdmiralYoda

I'm a DIY'r and like to fix my own stuff...one problem at a time.  But you have something like 10 variables working  against you on this boiler.

Find a steam pro on this site for help.  It's one thing to have an inefficient setup.  It's another to have a ticking time bomb / CO problem on your hands.

Every single safety device on this boiler is flipping it's middle finger at you.  Not to be judge-y but it sounds like you have spent plenty of money renovating your house.  It's time to spend a couple bucks making your heating system safe.

This boiler can be saved.  But it needs a skilled pro, not a well intentioned homeowner.  Sorry to sound harsh, but you have to draw the line somewhere.

foresthillsjd

@AdmiralYoda, I appreciate the honest advice, and trust me, if I could get someone from this site to come look at this for me, I would.  I have reached out to several, and no one is available this week, so I am just trying to keep the house warm without running a bunch of space heaters 24-7.  

And I am also just trying to make myself an educated consumer.  I hired a licensed plumber to install the low water cutoff and to skim the boiler.  The fact that the skim port is still plugged is disappointing and maddening to me. (I wasn’t home when the work was done because this was a company that came highly recommended)  I also tried to hire two other plumbers to install main vents and insulate my mains.  They both told me it was not worth the time or expense, so I grabbed a friend and we did it ourselves.  

I work in real estate development and manage teams of MEP subs.  I appreciate how valuable a skilled professional is, and I rely on their expertise.  As lovely as everyone in this board is, I would much rather get someone knowledgeable to fix this for me rather than having to look up the wiring diagrams of all of these things.  (So please, if you are out there, DM me!  I am open to replacing the boiler, I just want to make sure I find the right person to do it this time.)

But I don’t believe any of the problems I am currently experiencing point to an immediate safety issue. I would argue that the fact that the fact that these things are tripping shows that the safety systems are working.  But, I’m open to listening if you think it’s not the case.  Regarding carbon monoxide, I have a detector in the boiler room, another in the basement, and 9 more in the house, all linked by hardwire.  I haven’t had a CO issue since we cleaned all the carbon from the boiler, and I plan to get a combustion analysis as soon as I find a person who can come do it.  And the rollout switch hasn’t melted yet.  

I sat with the boiler again tonight, and the pressure isn’t even getting to 1 psi before the thing shuts off.  The boiler is not leaking water, and the auto feeder is working correctly. For some reason, the new LWCO is triggering even though the water level is fine.  

It seems to me two things are likely.  One, the LwCo was installed incorrectly, and/or two, I need to skim the boiler.  Those are easy enough to investigate before sending the boiler for the landfill.  

Again, I thank all of you for your advice.  You have been really helpful and great.  I really just want to get this straightened out so I can worry about wrapping presents and baking pies instead of combustion and carbonization (words you don’t want to hear next when it comes to presents and pies)

-Jackie

foresthillsjd

danitheplumber said:

Was there any corrosion on the block? I see corrosion on the side. It may be worth spending the money on a new boiler rather then trying to rebuild old one just to find it rot out a year later. 

How do I check for corrosion on the block?  Are you talking about the corrosion on the jacket by one of the drains?  Believe it or not, that used to be the only drain on that side, so the weekly blowdown had to come from there.   We had to put the bucket as close as possible, but inevitably some water would seep down the side of the jacket.  

danitheplumber

When you took off the top and side jacket. Not sure how many pictures you took but that's when you would see rot like metal flaking of the cast iron sections.

foresthillsjd

neilc said:

did the boiler shut off at the thermostat, or cycle off by pressure? OR, did you have to reset that LWCO again? previously I think you said you had to reset the LWCO, the most recent post said "the new 67M LWCO is definitely not shutting off on low water", which? the white wheel inside the Ptrol should get set to 1, the scale on the front might get dialed down just a bit more, any extra pressure the boiler is making is pushing water into the returns, the sightglass looks a bit dirty, like scum on top of water dirty, the skim port is still a factory plug, Sooo , , ,

The boiler shut off by the LWCO, but I don’t know why, since the water level is fine (middle of sight glass).  All I have to do to get it to turn in again is push the reset button on the LWCO.  

Would surging cause this?
  

Jamie Hall

When the new low water cutoff was installed, did anyone check that the connections to the sight glass were really clear? I hope? Easy enough to find out: operate the blowdown valve. The LWCO should trip, and you should see the water in the sight glass drop -- probably dramatically -- quickly.

If the new one is, as I presume, the 67 mounted on the front of the boiler, it is mounted correctly as to water level -- for an automatic cutoff. In my humble opinion it is set too high for the secondary manual cutoff, but that may be just the way the picture shows it.

In any event, when you drop the water level in the boiler with it running, the boiler should shut off when the level reaches the automatic LWCO, and, if you stop there and add a little water, should come right back on. Dropping the level further should trip the manual reset one -- but that should never happen, as the automatic one should do it.

If the automatic one isn't working that way, you need to find out why -- and get it fixed.

ethicalpaul

The boiler shut off by the LWCO, but I don’t know why, since the water level is fine (middle of sight glass). All I have to do to get it to turn in again is push the reset button on the LWCO.

Just so I'm clear...you were at the boiler watching it when the LWCO shut down the boiler?

ChrisJ

Judging by that gauge glass and the plug in the skim port I've got a feeling it's blowing its water up into the mains

KC_Jones

Pictures make it tough to judge sometimes, but that header doesn’t look like the correct size, it appears to be 2” and it’s supposed to be 2 1/2” minimum for that boiler.  Not that it relates to your main question, just an observation.

For clarity 2” pipe is 2 3/8” outside diameter and 2 1/2” pipe is 2 7/8” outside diameter.

foresthillsjd

@KC_Jones the outside diameter is 2 7/8. (Thanks for translating pipe diameter to outside diameter.  I wouldn’t have known otherwise.)

@Jamie Hall here are the dimensions of where stuff is mounted. The target water level line is not marked anywhere on he jacket, but the instructions say 23 13/16 (presumably from the bottom of the  jacket?). That seems much higher than the auto-feed level.  Should I top off the water past what the auto-feeder is doing?

I warmed the water to about 140 degrees and then drained the boiler from the blowdown valve until the water stopped running.  I added a little water and repeated a couple times.  I also removed the sight glass and cleaned it, and also drained all the muck from the bottom using that little nut. 

Yesterday was an usually warm day, so I turned the thermostat off and we managed on space heaters, but this morning, it was 57 in the house, so I had to turn it on again.  I have at least one guy who is available next week for a combustion test and to do a proper skim, but hopefully with the water a little cleaner, I can eke by until then. 

Jamie Hall

Generally speaking the water level should be somewhere in the middle third of the sight glass -- which is, or should be, somewhat above the feed level of the automatic water feeder.

The dimension given is from whatever the boiler is sitting on -- floor, cement blocks, what have you. However, judging by the figure with the tape measure, the manual number looks as though it will give you a good working water level.

Autofeeders are a little tricky. Most newer ones have a way to set a time delay on feed, and also a way to set the volume fed. Sometime take a look at the way your water level behaves when the boiler shuts down. What you are interested in is how long it takes for the water level to stop rising -- which is when all the condensate has returned. The autofeeder time delay should be at least that long, to avoid overfilling the boiler. Then for the amount to feed, sometime when it's warmer perhaps, record the amount of water -- in gallons -- which it takes to go from the normal water level to the level which it reaches after the autofeeder trips and the time delay has passed. That, then is the amount of water you want the autofeeder to feed after the time delay.