Riello RS 28 Power Burner

MechanicalJonny

Hey guys. Does anybody have experience with Riello Power Burners?

I've recently acquired a job to look after a boiler in an old apartment building. It's a De Dietricht gt 307 boiler with a Riello RS 28 power burner.
I've had to open the boiler up to break out old swollen baffles and replace with new ones, but the boiler had been running horribly probably for its entire life.
I did a combustion analysis test on it with these results:
CO2: 12%
O2: 2.6%
Excess air: below 10%
CO: through the f*ckin roof.

I went through manufacturer instructions to set the power burner up again. Figured out what the instructions required for gas delivery on the manifold side, and same thing with air delivery. It seems like my gas differential pressure is good, under full fire, it sits at 2.45" when high firing, and then seems to modulate down to below 1" wc. The boiler normally low fires during the summer to supply domestic hot water demand (Turbomax Indirect Tank).
I had just introduced a larger combustion air (there was only a 5" flex duct supplying the room before). I installed a 12x12 combustion air and put the old flex duct up high for my ventilation air. 

I try adjusting the air adjustment screw on the top of my burner, but I can't seem to get any more excess air through the combustion chamber. Any suggestions?? Riello tech support is MIA.

EBEBRATT-Ed

I worked on a lot of those burners.

As far as gas pressure at the head of the burner goes you need a manometer with two tubes (high and Low)
Look in the reillo manual they show a diagram showing how to hook up the manometer to read furnace pressure or draft (your probably pressure fired) and gas pressure at the same time so the gas pressure has to be above the furnace pressure.

So, for instance, if on high fire you want 2,5" of gas pressure and your furnace pressure is 1" of wc then your real gas pressure is 3.5"

There are good burners especially on gas You have to set the screws on the cam adjusted correctly and you have to adjust high fire first and work your way down to low fire in increments. The opposite of all the American burners

The little fitting on the top of the burner that looks like a barb fitting is where you measure the gas pressure at the head of the burner.

Do you have the burner manual?

GGross

I don't have much experience with external power burners, I mostly look at new condensing equipment where I am setting an incoming gas pressure to the appliance, but that book would appear to be using a "delta P" or pressure differential value for gas pressure, and I only see one tube on your manometer. I could be mistaken but I do not think that book is telling you to set your pressure at 2.5, but rather the pressure differential at 2.5" I would imagine the book will tell you how to properly measure and set that value

EBEBRATT-Ed

I sometimes disagree with burner MFGs and have had problems with many that DONT do adequate testing.

Riello is NOT one of those at least in my experience with their burners that I worked on if you could set them by the book they work and work well

MechanicalJonny

Hey guys thanks for the responses. Yeah I had to measure the gas and air pressure separately. I'll have to swing by with a differential pressure manometer sometime and see what it says.