Oil heat CO2 is Too Low

[hockey]

My boiler has a 1GPH 60 Degree SS nozzle. There's no nameplate anywhere but each service tag uses this nozzle. I adjusted for trace/zero smoke and I can't get the CO2 any higher than 5%. Draft is perfect (-04 & -02). Flue temp is 460 F. Unit is original (30 years old?).
Is ther anything I can do to get more efficiency?

[Noel Murdough]

Check your CO2 at the breech, and over the fire.

Are they the same?

Adjust the breech draft so that you get a slightly POSITIVE reading over the fire. Check your CO2 over the fire, and in the breech.

Are they the same?

Are they now the same as before?

Reset your draft to where it belongs.

If they were different, what does this tell you about draft leaks in the boiler itself?

Seal up the boiler so that all of the readings stay the same.

What SHOULD the boiler be fired at; that's the real question?

Noel

[once and done]

did you check co over the fire and then at the flue. if you gain more then 1% you have boiler leakage and are sucking air into areas of the boiler from doors port holes etc. whats the 0 reading. 450 at chimmey a, not much heat transfor in boiler, guess they burn lots of oil. your firing a 1 gph, you may want to try a bigger nozzle.

[oil lp man]

How accurate are your instruments?
5-7% co2 might be perfect for a 30-40 year old boiler.
What is the make and model of the burner?
That will tell a lot.
If the burner is a 1725 rpm with a non flame retention style burner then 7% or less is about right.

[beenthere]

Time to change fluid maybe.

Does the boiler have a btu rating that is still readable, is so, is it 140,000 input, or is it alot more?

1725 rpm, non retention head burners do poorly when down fired.

[hockey]

I found a sticker on the Beckett Burner. It's a Model SR Burner, MP1192. Sticker says .40 2GPH! 1725 RPM. Begs the question: Why is there a 1.0 GPH, 60 degree nozzle in it? What's up with that? What can I do? Total Heat load is 70,000 BTU's (FHW and Amtrol 41 gal).

[cem-bsee]

I don't understand the measuring of CO2 -- the same chemical in some extingushers [ sometimes used for quick cooling of beer ]= Carbon Dioxide --

Are you meaning CO? -- Carbon Monoxide

[jdenyer]

Is that .40 to 2.0 gph? Most burners have a wide range of firing rates. It's the boiler that determines the nozzle size thats needed. Noel is right on. Sounds like air leakage. We see it all the time on older boilers. Do the tests he recommended and then seal up any air leaks.

[hockey]

I mean carbon Dioxide (CO2). Generally, if the CO is high, the CO2 is low and vice versa. "Perfect" combustion is a 12-13% solution of CO2 in the combustion air. 12% is most efficient; 11% is considered most reliable due to supply air temperature swings.

[hockey]

I see "Mills" on the boiler body. That's all. The burner says, ".04 2.00GPH". That's how it's written. I took samples with a long tube above the fire (tube got cherry red). CO2 reads 5 1/2% over fire and still 4 1/4% in flue.
It's a new nozzle. Boiler water gets to 180 deg temp. Sounds like poor air/fuel mixing but there's no smoke! Should I try a hollow instead of the semi-solid?

[Noel Murdough]

Air leaks in that boiler.

That old beast won't get much better.

Noel

[casturbo]

I've worked on that SR Beckett burner lots of times (unfortunately!), that's a really old Beckett model. HO should be advised in today's world of oil prices, that burner is wayyyy outdated and is low efficiency. That being said, the nozzle you described is fine if it's burning and starting OK. On that particular burner, nozzle configuration (spray angle or type) never seemed important, there's just not enough air pattern it appears to warrant a particular nozzle. Maybe at least suggest replacing the burner with a Carlin Elite or Beckett AFG.

Low CO2 is because of air leaks in the boiler or the burner being overaired to compensate for a dirty flame. Find the right nozzle to obtain the cleanest flame with the highest CO2 reading......but in reality, that burner was designed to just burn oil and make heat, efficiency was wayy down on the priority list. If it were me, I'd probably try out a 80° spray angle nozzle or at least boost the pump pressure up to 140 psi, then retest.

[hockey]

Casturbo, thanks for your help. It's my boiler! I haven't checked the pressure yet (I'm waiting to get my gauge returned). The Amtrol uses 275 gallons during the summer months to heat the hot water. That's alot of oil/money, huh?
I am seriously leaning toward an electric water heater. Sounds like a payback in 2 years.