co testing

Paul_69

i was checking a gas atmospheric boiler and the ppm was 600. after cleaning boiler, burners etc. i was able to get it to 200 or so ppm co. checked gas pressure. is it because its 20 yrs old? plenty of combustion air as well. is there any info out there to better understanding what i should be looking for on different units and how to use electronic tester better as instructions say very little. i am a contractor and just bought a tester and looking how to test and correct problem readings with heating equipment.

JStar

CO

What were the other readings during the test? O2? CO2?

Tim McElwain

Paul, what is your location

as I have a training center and from time to time I run a class on Testing Design Gas Equipment. You would find it very helpful to attend.

Paul_69

test

7% 02, didnt do co2. i live in sharon mass 02067 tim. it is obvious i need training.i am new with testing electronic equipment. is the co reading i gave scary or acceptable.

JStar

CO

At 7% O2, you're slightly underfired. If the gas is maxxed out at 3.75", can you adjust/lower the primary air on the burners?

Tim McElwain

Paul 600 PPM is defintely too

high we shoot for less than 100 PPM air free? Have you clocked the burner to see what rate it is firing at, you can do that with the 1/2 foot dial on the meter and a stop watch. Check to see what the input should be on the rating plate for the equipment.



What is your inlet and outlet gas pressure to the gas valve?



Adjusting primary air to the burners will not do anything other than change the burner flame characteristic which should be a soft blue flame not roaring or lifting.



Sometimes just taking the unit apart and cleaning can bring the 200 PPM you were able to get after adjustment to less than 100 PPM air free.

Jim Davis_3

CO testing

Something that didn't make sense with the question is that you had a CO reading of 600ppm.  This boiler would have more than one burner therefore there should be a reading for each burner.  If there is a round drafthood on top, it must be traversed from left to right for the highest reading.  The highest reading must be watched for a couple of minutes to make sure it doesn't change. 

If the drafthood is in the front or rear then CO readings from each and every burner must be taken and watched to make sure they don't change. 

I have a feeling the CO is not staying the same which could indicate a major safety issue.

Empire_2

Hello Paul;

Bacharach has manuals for procedures in performing a combustion test.  Choose an instrument and inside the article or manual, you can read procedures, placement of probe, and description of what different changes you make and it's effect on your final reading.  I believe Testo has similar literature.



Peace;



Mike T.

Jim Davis_3

testing

Actually neither Bacharach or Testo show the proper way to test a boiler with a drafthood which is why most are tested incorrectly.

SWEI

Testing a draft hood

Got a pointer to the "missing manual" for this?





thanks~

Jim Davis_3

testing location-CO

As above, the round drafthoods have to be tested on the left, center and right.

Rectangular hoods allow for each burner to be tested independantly.

Tim McElwain

The proper testing procedures

are outlined in my manuals and also Jim's companies manuals. Most instructions I have seen on combustion testing are incomplete. The problem is that if you do not test properly you may get an excessive O2 reading which then changes the entire combustion picture. There is much to learn that is why Jim's classes and mine are typically three days. Just buying a tester and thinking it will do everything for you is a mistake.