Unusual Laars CO problem

toearly_2

Encountered a problem today that has me stymied.

Teledyne Laars JVH75NCSS

This is a draft induced boiler.
When checking for function the CO meter started picking up 2 PPM several feet away.

After the jackets were removed we found the meter peaked at 21 PPM near the inducer
All connections to the inducer are sealed
No signs of warping or other wear on he collector box, inducer

When meter is placed on the floor near the burners CO reading goes down

No signs of leakage other the CO meter saying so

I have spoken to Laars and was informed they are going to fire up a boiler to see of they can create the same problem or find a leak

Actions I am going to take in AM

Shut off gas an introduce smoke when inducer is running
Soap test inducer and collector box when inducer is running

Negative pressure on one side
Positive pressure on the other side

My thoughts are there must be a leak on the positive side

???? Seals on shaft ???

Any thoughts you might have will be welcome

David

jim murtaugh

co

is this vented to a common flue with another appliance?

toearly_2

Sidewall vent to the outdoors.
I also checked for blockages

David

mark_40

why ??

care if you have 21 ppm ??? what did you have in the flue, .

Mark Hunt

Because


there isn't supposed to be ANY CO spilling into the space. Period.

And who could guarantee that it would stay at 21ppm?

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

toearly_2

> there isn't supposed to be ANY CO spilling into

> the space. Period.

>

> And who could guarantee

> that it would stay at 21ppm?

>

> Mark H

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 238&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_



> there isn't supposed to be ANY CO spilling into

> the space. Period.

>

> And who could guarantee

> that it would stay at 21ppm?

>

> Mark H

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 238&Step=30"_To Learn More About This

> Professional, Click Here to Visit Their Ad in

> "Find A Professional"_/A_

toearly_2

Mark, Thank You as we are on the same page.

It is going to be a matter of finding the leak.


Smoke and soap @ 9:30

Mark Hunt

Let us know


what you find.

And THANK YOU for testing!!!!!

Mark H

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Unknown

Remove the inducer

and reseal around the connections with a silicone sealant temp rated 400 degrees or higher. I had a similar problem (not the CO) but when soap testing around the positive side of power venters that the seal between the power venter and the ventpipe was leaking and also the seal on the power venter. Make sure depending on how it is attached that both the negative side and positive side are sealed as sometimes on cold start you will get a back pressure until it warms up.

I would also after that is accomplished do a combustion test as that style boiler can sometimes need adjustment for maximum efficiency and also to lower CO in the flue gases.

You can test by tapping a hole into the vent after the inducer. Just make sure to seal it afterward.

mark_40

21 ppm ....

could be from a gas stove ..... what did you read in the Flue ???

Larry (from OSHA)

mark@climate

Mark,

I'm curious about your perspective. I certainly agree that what is in the flue is very important, but, as the 21 ppm level was at the exterior of the boiler, I would guess that there is something that is from the boiler and not an appliance somewhere else in the house that is causing the slightly elevated levels. However, to follow where I think you are coming from, I was in a trucking warehouse the other day (12 LP forklifts) and there was 8 ppm in the office and nothing in the warehouse. Of course the majority of the 30 dock doors were open so the pressure differential could have been a factor. I find the occurence of CO in unexpected locations to be of particular interest to me and any discussion on this subject is really appreciated. My experiences and perspective is really quite different from what is normally discussed here, but I do always look forward to the opportunity to learn and possibly apply it to what I do.

Larry (from OSHA)

mark_40

if you don't know .....

what is in the products of combustion .....how can you say .... it's the BOILER ??????

Unknown

mark@climate

I am just curious to know who you are.I have noticed a few of your posts here and your name is new to me. You have been pretty quick to counter some points made here and seem to be very knowlegeable about gas and other related subjects. Welcome to the Wall just fill us in a little bit on who you are.

toearly_2

Thank You to all who have replied.

Thank You to all who have replied.

Here is what I found.

It was my goal to find the leaks before we jumped in and removed any parts.
Smoke test showed nothing. Which was not a surprise? Soap and water showed a fair amount of leakage at the transition connection from the inducer to round pipe. Visual inspection showed caulk.

Now that we knew where the leak was we jumped in and started removing parts.
On this boiler there is a damper / flapper. This had a layer of fine corrosion on it that had fallen down the vent pipe. This flapper was free when moved by hand. It appears that there was just enough weight on it to prevent it from lifting high enough to function as designed. The transition was removed and sand blasted clean and reinstalled with new sealant. When checked, the readings would fluctuate. Factory was called and they were undecided if the damper was needed as the new boilers do not have the damper. Rather then remove the damper; it was secured in a position and that gave us the desired results.

Thinking about it after the fact and all is running. We just happened to be in the right place at the right time to catch a failure before it occurred. It only would have been a matter of time before the flapper closed enough to prevent the boiler from firing.

A small void in the sealant allowed a CO leak to surface in the room.

Thank You again to all who have replied as any and all thoughts always help bring closure

David