what amount of flu gas should you have in the flu and why?

Jerry_3

Can anyone tell me what amount (ppm) of flu gas I should get when I take a reading in the flu, and why? If the level is to high, what would cause this, and how to correct????

Steamhead

PPM

of what exactly? Carbon Monoxide (CO)?

The answer would depend on what equipment you're working on, and what fuel is used. For example, a gas-fired boiler should not produce more than 400 PPM of CO, measured "air-free" (undiluted). A good service tech will try to get the CO down as low as possible, preferably less than 100 PPM or so.

Tell us more about what you're working on, and we'll try to give you more specific information.

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

Jerry_3

flu gas

The system is a hot water boiler. a stse program did a test in the flu 3 times. One reading was around 1700 ppm, one around 1200 ppm, and the thrid around 1500 ppm. I am new to this combustion analyzing don't really undrstand why and how. Any ideas too find info would be helpful.

Steamhead

That's way too high

and dangerous. If you're new to this, it's best to call in someone to correct it. Try the Find a Contractor page of this site.

The best way to start learning is to read Tim McElwain's training manuals. If you can, go to his seminars also. Tim will send you a catalog if you e-mail him at gastc@cox.net . Start with the Fundamentals manual as it has an excellent Carbon Monoxide chapter.

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

Jerry_3

flu gas

I will check into that. The reading in the flu was CO. And it is natural gas boiler. Could this be due to lack of combustion air? and/or improper air shutter adjustment? I was also told that it could be a pressure problem with the gas valve? Thanks for all your help and information!!

rudy_2

CO/Combustion test info

We've got alot of information up on our application web page at www.bacharach-training.com .

Hope you find some helpful info there.

Chris V

Possible causes

A few Things I would Check: Are Burners clean of Lint/dust?
Is there flame impingement of the burners on the bottom of boiler? Is the gas valve set to the correct BTU input of boiler( This is checked by clocking the meter) Someone along the line might have opened up gas valve to make a larger fire. In any case, the co readings you have are VERY dangerous and I would Call in A Pro to Correct the Problem ASAP!Hope This Helps.

Unknown

Jerry - High CO

readings in the flue of a gas boiler is a definite indication of a combustion problem. The boiler could be overgassed due to improper gas pressure. Check with a U gauge (manometer) and match up to pressure on rating plate. Then clock the burner using the 1/2 foot test dial on the gas meter, two rotations timed and then divide number of seconds into 3600 that will give you cubic feet. That should then be multiplied times the heat value of your gas (usually 1000 to 1075 btu's per cubic foot). That should match btu input from rating plate.

Make sure boiler sections are clear and clean.

Check draft at diverter and over fire. It should be -.01,
-.02 -.03 .

Determine if you have sufficient air for combustion using procedures outlined in NFPA 54/ANSI Z223.1 National Fuel Gas Code section on air for combustion.

You also want to make sure the air shutters are not closed or plugged on the burners and the flame is blue and steady.