boiler help

grumpyjoe

What do you think about changing an atmospheric fired boiler from a draft hood to a barometric draft control?

Brad White

Change the boiler or change

the venting setup?

If an atmospheric boiler has a draft hood, either integral or AGA, that has to remain for the installation to be in accordance with its listing. I do not believe it can be done without negating the listing and incurring liability, nor do I see an advantage if that is what you are doing.



If you mean go to a forced draft type system (e.g. a boiler made for gas or oil but set up with a gas power burner), then a barometric damper is most common.



But for the expense, I would invest in a ModCon boiler appropriately sized and vented by the book. I hope this is possible, the venting conditions seem to drive what is possible despite the many sanctioned ways they can be vented.



Did I gather your question correctly?

grumpyjoe

boiler help

I have an old repco hot water boiler, and a weatherization project has changed the existing draft hood to a barometric damper in the flue. I am now having a problem with flue gas. I understand the physics of draft and the danger of co, I feel as if they made a bad choice in this change.

Brad White

I agree

I can see no advantage to changing what has been factory tested and approved. (OK talking Repco here, but still, there is an AGA listing for it when it was made).



The fact that you are having a flue gas problem underscores both of our assumptions and experience.  How has the flue gas issue presented itself to you? CO detectors? Moisture on glass? Please tell.



Not to make light of such things, but were you happyjoe before this happened?

grumpyjoe

boiler help

The problems are, noxious smell (sulphery) black dust, a black line down the middle of my tongue (gross). It seems to be accumalative. to say it gets worse as the day goes on to the point that I have to turn it off and air the house. Once at 2:00 a.m. because it stunk so bad I could not sleep. I have a co detector and the flue gas has been measured at 21 parts per mil. they installed this control to pull more air across the burner because the co was high.

as for grumpyjoe, it's a nickname I got from long ago.

Brad White

I suspect

that you also do not have sufficient combustion air, this is more critical or as critical as what is leaving the house. Was the basement air sealed as part of these recommendations? A fan in a can device might be needed.



Get a pro in there TODAY.



OSHA regs aside, (which allow 35 PPM as a time weighted average for an 8 hour work day, are they kidding), your CO level should be ZERO unless you smoke or have a gas pilot range. Then you might see 8-10 PPM background. 21 PPM in the flue gas? Or the living space? 21 PPM in flue gas itself is low, a good thing for that type of appliance. Usually 100 is acceptable and that depends. Anything over 400 needs attention or a lock-out.



Sulfurous odor typically is not a gas condition, more geared to oil. You do have gas, correct? Just a point of understanding/information.



I was only teasing you on your nickname.

grumpyjoe

boiler help

The 21parts was in the flue. As for the smell, it is ,as a better description,  exactly like the smell of a non-vented kitchen oven. kind of like from a catalytic converter on a car. I have natural gas. the co # were high. that is why they put on the barometric control. they did seal the house, but the smell started the day they changed the configuration, before the sealing job.

Brad White

If there "is"

a barometric damper, is it at least operating correctly, tipping/drawing in when there is a windy condition outside?



As stated, 21 PPM in the flue (before dilution) is not bad. What was the number before?



Is there a spill switch on that draft device? Code here in MA and good practice everywhere. Your situation sounds like spillage and the problem may be downstream of your draft device.

grumpyjoe

boiler help

I'm not sure that the 21 is before dilution. the draft control opens when the boiler fires and seems to be working. the #s they quoted before they changed things were (are you ready?)

2000 ppm yes three zeros.

Before the draft control was installed the flames in the boiler were natural and fairly Quiet. now, they( the techs.) have so much air coming into the bottom of the firebox that it sounds like a jet engine.

Charlie from wmass

Did they install a liner?

I have come across several undersized liners being installed.

grumpyjoe

boiler help

No they didn't. it is the original brick chimney. I've thought that maybe it has a crack or defect and the additional volume is making it show up. the fumes are sort of on a delay.20-30 min. after the burn. It also seems to accumulate as the day goes on. the last time they came to check the system because I complained, we had 25 to 30 mph winds and they were fanning the doors going in and out to their van, so they couldn't smell anything and concluded that nothing was wrong.  

Charlie from wmass

Any photos you can post?

sometimes the devil is in the details. I must say I disagree with adding a barometric damper for a boiler such as this. I am wondering if what we are thinking and what you have are the same thing?

Gordan

Are you sure that's a barometric damper?

Sounds like just a straight-up automatic flue damper. Is it mounted atop a draft relief hood? Got a picture?

grumpyjoe

boiler help

I am Going to try to send pics. 

grumpyjoe

boiler help

It said the pics went, but I'll try again

grumpyjoe

boiler help

one more view

Brad White

Oh boy...

What you had originally is not your typical AGA draft hood but is acceptable in most jurisdictions. It is a type used for longer horizontal runs, but should have been just fine in terms of compensating for draft variability in the chimney. Not so great for energy efficiency because it is always drawing air up and out of the house, but thinking safety, I would be OK with that provided the chimney had good draft to start with.



What you have now is indeed a barometric damper (Flair Co. is a typical manufacturer), but I would have put that downstream of the vent closure damper. Even though the vent closure damper fails open and has to open to fire, I do not want any unnecessary resistance between my chimney and my barometric damper. To do so creates a condition where it is sometimes easier for the flue gasses to leave the barometric damper to the space than to go up the chimney.



Thrown in bath fans, kitchen fans and dryers and that too can contribute to fighting the chimney.



The other pros here may have different opinions, so this is just what I see.

grumpyjoe

boiler help

Thanks to all who replied to my plea. I am kind of at the mercy of the weatherization people. I am on disability from a work accident, and we all know that fixed income leaves little $ to do much with. I will consider all the great advice and relay it to the technician.

thanks again and if you have any other thoughts, I'm all ears and very appreciative.

God bless,

grumpyjoe

Charlie from wmass

The draft hood that

looks like a mushroom maybe a better choice. Looking at the first photo I wonder if the boiler had one where the different colored pipe is on the vertical riser. The barometric damper may not be adjusted properly. The automatic damper may have a plug that needs removed if your boiler has a standing pilot. 

icesailor

A Mess?

#1.

Where's the water heater?

#2.

I think that install/modification totally violates the UL listing for that appliance.

#3.

The smell is because the draft resistance is so bad that exhaust gas is getting into the building. If it isn't rolling out of the bottom of the burner, there's another source. That smell on the back of the tongue or sinuses is from Aldehyde. A 100% indicator if flue gas leakage.

Someone needs to take something a UGI CO71A and go around to look for the highest levels of CO and fix it. There isn't enough combustion air. The draft needed isn't high enough to overcome the resistance of the weatherization job.

This is what happens when you hire a bunch of rookies or no-nothings, give them a class with someone who knows barely more, and send them out in the world.

Sinful. Simply sinful.

grumpyjoe

boiler help

The hot water heater is about 10" from the chimney. they also modified that. It was a 3" flue pipe, and they increased it to 4",and just put it on the 3" draft hood or collar of the w. heater. Everything worked fine until they installed the barometric damper.(this job has been going on since feb.2nd). the fumes started before the air sealing, so although it has gotten worse as they tighten up the house. The initial change of the hot water heater flue and the draft hood on the boiler, started it all. 

thanks

JOE