Nozzle size

Scotth48

Replacing my oil fired boiler with the same 4 section unit but a different brand. My house is about 1300 sq ft on each floor for a total of 2600. My old boiler came with a 1.25 nozzle and we used a 1.0 nozzle without any problems. 
The new burner uses a 1.5 nozzle for a 200,000btu rating. 
Can I go smaller on the nozzle size that would be more in line with the old boiler? 1.0-1.25 gallon.

Thanks.

bburd

Your new boiler is too big. How was it sized? If the house did fine burning 1 gallon per hour you don't need a boiler that can burn 1.5 unless you are planning a very large addition.

Steam boilers are sized by measuring the radiators. Hot water boilers are sized by calculating building heat loss.

SuperTech

Wow. Are you heating the house with all the windows open? How was the boiler size determined? A 3 section would have been more than enough.

As far as the nozzle goes, the manufacturer usually specifies a few different firing rates depending on oil pump pressure and nozzle size. But you need to perform a combustion analysis after changing nozzles or else you can't be sure the burner is operating properly or safely.

HVACNUT

2,600 sq ft and approximately 160,000 net BTU, that's about 60 BTU per sq ft which would be excellent if you lived on Pluto.

Go with the 3 section. 
What make and model? What burner?

STEVEusaPA

HVACNUT said:

...would be excellent if you lived on Pluto...

I don't know of an additive that would keep the fuel from gelling down to -387°F

jesmed1

Just for comparison, my 4800 sq ft, 100 yr old condo building in the Boston area could be heated by a 1.0 gph input rate with margin to spare.

As others have said, unless you are somewhere above the Arctic Circle, you have way more capacity than you need.

Grallert

This is an extremely oversized boiler which makes me question the installer.