sooted sections

mitch moore

New customer has a 270,000in standing pilot,Utica, hw boiler that was sooted up. No model# unit aprox 10yrs.old. It vents into aprox.30'vert.mason clay lined chiminey on outside wall vent come directly off unit 6"single wall 2' vertical with 90*elbow(only counted elbow as TEL 1') then 2' lateral to chiminey,no draft -hood.Gas pressure was adjusted/corrected from 2.5" to 3.5" was rolling out high heat at burner section b-4 and after adj. Cleaned sections and rechecked no rollout of heat. This boiler was oversized for this application and I belive some at some point tried to derate. I realize the stack is too small and have to take corrective action. NFGC book states(and it's probablly less because of the elbow TEL under estimation)196,000btu max- if I were to change the single wall to B-vent it shows 198,000 (is this correct?)If I add a draft hood will it increase the capacity of the chiminey by introducing air with the flue gases or decrease the capacity, I don't understand the principle or reasons for draft hoods I noticed some boilers come with them some don't When if ever is it manditory?

mitch moore

correction

the flue pipe is 8" off the boiler and the clay lined mason chiminey is 6"

peter desens

Factory help

Mitch,

Please feel free to contact our Technical Support team at 1-800-325-5479 for assistance in this matter.

Peter Desens
Technical Services Manager
ECR International - Utica Boilers

mitch moore

Thanks

Peter thanks for the response. Much appreciated.

Dale

No draft hood?

I wonder, sometimes the draft hood or diverter is hidded behind the boiler, standing pilot needs a draft hood, a standing pilot conversion burner needs a barometric. I think you need to line the chimney but I would take some flue temp readings and clock the gas meter to see what the input really is.

mitch moore

No draft hood

It takes air from a built in diverter behind the front panel of the boiler.Did not take the stack temp or gauge the draft.The chimney is already lined with clay.

Dale

The diverter

The diverter you speak of is that manufacturers draft hood. DO NOT add another one or you'll really have a problem. Sadly I see this done on a fairly regular basis and the extra dillution air get the stack temp way too low and can spill flue products.