Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

High CO on Fulton Pulse

RPK Member Posts: 96
A colleague of mine is looking for help with a pair of Fulton Pulse boilers. I don’t have all the details but I told him I would post here and see if anyone could help.

Model # PHW1400SM. Combustion measurements were taken prior to servicing and were acceptable according to the IOM. 6%O2, CO below 100ppm. The flapper, gaskets, and whatever else comes with the annual maintenance kit was replaced on both boilers. Apparently now the CO is quite high (700PPM) and O2 is still at 6. Same thing happened on both boilers. Per Fulton tech support, 5-6 is the highest O2 percentage they allow or it causes other issues. Stack temp around 250 degrees (both boilers, before and after the maintenance was done).

Any ideas?


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,386
    edited April 2019
    Replacing flappers and gaskets tells me you may have something mis-aligned, or reinstalled incorrectly. Or maybe the replacement parts are not the correct ones.
    You didn’t change any orifices, and you confirmed gas pressures? Seems odd that both worked fine and now both are equally wrong.
    What were the rest of the combustion numbers?
    EBEBRATT-Ed Member Posts: 14,560
    Did your run it long enough to get it up to operating temp? The same way a cold pot of water on a gas stove will make Co so will a cold boiler.

    I would recheck the parts you replaced as the first step.

    lack of air through the burner will cause HI Co and low O2. Conversely too much air will cause HI Co and HI 02. Since you are on the high end of the 02 you could reduce the air slightly and try it

    I would check the replaced parts first, you don't want to get it all out of adjustment for nothing.

    I searched on line apparently that boiler is discontinued by Fulton, They have no service manual on their site. I found it on some other sites ........It basically tells you nothing much about combustion. Adjust air flapper, adjust gas flapper blah, blah

    Unfortunately that thing sounds like a dog from what I can find

    Also 100ppm is no great shake. Should be below 50