Smallest Oil-fired Hot-Water boiler out there?

Steamhead

One of our customers wants to replace the down-fired W-M 2-68 that's heating his addition and indirect tank. No, it hasn't been plugging up, just thinks it's getting old. Haven't gotten the heat loss done yet, but the 2-68 still appears oversized for this job, hitting high limit frequently.

The smallest one I've found so far is the Burnham MPO-IQ84 and its Force clone that Ferguson sells. These fire at 0.60 GPH. Anyone know of anything smaller?

DJD775

Biasi B-10/3
https://qhtinc.com/biasi-products/b-10/

HVACNUT

DJD775 said:

Biasi B-10/3 https://qhtinc.com/biasi-products/b-10/

I wonder what burner is used. Maybe my file isn't up to date but it shows a .67 input with the Riello F3. Carlin 2 stage?

EBEBRATT-Ed

Peerless and Crown are .60 input. Peerless has condensing oil that fires.50 but I am sure you want no part of that

EBEBRATT-Ed

Yeah the Biasi says .51 firing rate, Carlin, Riello or Beckett

DJD775

HVACNUT said:

DJD775 said:

Biasi B-10/3
https://qhtinc.com/biasi-products/b-10/

I wonder what burner is used. Maybe my file isn't up to date but it shows a .67 input with the Riello F3. Carlin 2 stage?

I see 0.67 input in the Riello setup manual too. I believe at one point they were shipping with 0.40 nozzles but they could have switched back to 0.50. How is the MPO 0.60 input with a 0.50 nozzle @ 180 psi and the Biasi Is the 0.67 input with the same setup? Either way these are about as small as you are going to get for oil boilers.

HVACNUT

Buffer tank, primary/secondary piping, or an EK-1 Frontier with their water heater and get rid of the indirect. 

What type of emmiters and what size is the indirect?

Jon_blaney

How about an oil fired water heater. No worry about return temps, no buffer tank or indirect needed, plenty of dhw. Been doing it for twenty years with the same tank, BOCK 32e.

SuperTech

I don't think you can go wrong with an EK boiler. The Trio Pure Pro can be fired with an F3 Riello .55 60A nozzle. 75,000 Net BTUs.