Another member of these forums asked me a legitimate question regarding why I chose the P&M Ultimizer BL 34-44 over the Optimizer 250 gassifier for my home heating and domestic water application. I thought I would re-post what I told the person in hopes that it will benefit someone else that may be at the same decision point I was.

When I first started looking at OWBs it became apparent to me that the P&M brand was where I wanted to be. Initially, I thought I was 95+% certain the Optimizer 250 was for me. P&M told me a story about a 250 that was working awesome in Canada for a 6,500 sq. ft. old farmhouse.... again I thought I was on the right track. What "turned" me to the Ultimizer was a combination of items (not in any particular order):
1. OWB cost: $9,200 versus $11,500
2. Burn Times: BL 34-44 longer burn times due to substantially bigger firebox.
3. Ease of maintenance: not interested in maintaining Opt. 250 nozzles and Scotch HX tubes (although it looks to be quite simple)
4. Peak Output: higher peak BTU output (BL 34-44 >350,000 BTU/hr versus Opt. 250 up to 190,000 BTU/hr)
5. Simplicity: the Optimizer 250 simply has more items that need tending to than does the BL 34-44
6. Learning Gassification: "learning" how to best load the 250 for best burn times and less tending; me no want to learn that right now
7. OWB Design: big plus for the modularity of the Ultimizer design (if the water jacket were to have an issue, it can be separated from the burn chamber for repairs)
8. Fuel Options: nice to have the option of having a shaker grate to burn coal (I bought the shaker grate version of the BL 34-44

).
9. "No" Firebox Corrosion Potential: the refractive cement lining in the burn chamber (no corrosion at the ash line!);
10. Less Firebox Door/HX Door Corrosion Risk: the outer insulated door that keeps the loading door and HX cleanout door covered and protected from condensation.
11. Four Feet: There are four feet on the unit so a poured concrete pad isn't absolutely necessary. Four solid concrete blocks of appropriate size will suffice.
12. Efficiency: Simply put, the Ultimizer BL series is probably one of the most efficient
conventional OWBs on the market.
Again, I'm sure both are fantastic units but those are my thoughts at this point in time.
