Yes, B100 can replace HHO. But, there are “mixed reviews” on burning B100 without a minor modification. Some members have stated that they have had no problems putting biodiesel in the oil tank and firing up their burner. Others have reported failed startups, but a simple, available $36 line-heater right after the nozzle does the trick in getting back to a consistent startup. I guess the question finally comes down to what the variables are that cause some to be able to start without the line-heater and some not. It could be the temperature of the room where the furnace is, the way the biodiesel was made, nozzle size and spread, too much air through the air-vanes or …? You just have to play with it and find out how your burner does in your environment with the biodiesel you are making or buying. Becketts AF or AFG’s are a great place to begin. They’re readily available, replacement parts are fairly inexpensive and Ebay seems to be flooded with them and I’ve seem all sorts of parts there lately as well, so I would recommend starting your experimental veg-oil build with a Beckett.
I’ve been burning washed, homebrewed, B100 for two full seasons now and have had no issues, outside of having to change the filter due to all the gunk that biodiesel will clean out of an old tank. If your B100 is clean, go for it. You might want to start at a lower blend if you have any hesitations, and work up from there, but I can tell you all is well so far. Be aware that if your pump has rubber seals and gaskets they will eventually corrode and leak. If you do, get Vitron (sp?) seals installed and you should be fine. Drop me a note offline if you’d like to.
“Usually” B100 needs no modification or only minimal modification. WVO needs extensive modification. Usually a Beckett AFG can be configured for just about any oil furnace or boiler but you should check if it is listed by the manufacturer of your furnace or boiler for your model. Since you mentioned liter, are you in Europe? A lot of European equipment never came with Becketts and there are a very few American boilers and furnaces that won’t work with a Beckett. (some won’t even take a 4” diameter balast tube) If your equipment is one of those, it is usually best to get a spare burner of the same type that you already have to convert (if you are doing more than just a biodiesel fuel swap with maybe a commercial nozzle heater).
I’ve been lurking for a while and I’ve just started producing biodiesel for home heating (and also for my diesel VW). I’ve got a 25 year old Williamson oil furnace (.75 gph) and so far I’ve done tests up to 95% with my BD and all has gone pretty well. My tank is in the basement (around 55 F), so no worries with gelling the BD. So far, I have 60% BD in the tank and I’ve run into only minor problems relating to filter issues. This morning however, was another story. I awoke to find the house at 56 degrees and the furnace off. The furnace wouldn’t try to ignite at all. I checked a few things and eventually took the nozzle and adapter / electrodes out of the tube to check them.
There appeared to be some black soot / gummy substance on the outside of the nozzles and the electrodes were somewhat dirty as well. I cleaned everything, emptied the B60 from the filter, refilled it with heating oil and hit the reset button. Excitement! I thought the basement was on fire as it burned up the fuel already sprayed in the firebox. After a few seconds it burned off with only a little smoke. Somewhat alarming… Anyway, my question regards your statement above. Do you know of anywhere I could line up a spare Williamson burner unit (the number says 02-681) to experiment with? Can later burner units be adapted to install into my furnace as is? I’d really like to see what I can do to tune my burner to run reliably on B100. Perhaps a new nozzle (it’s currently a Delavan 70W) would help?
My own experience is that B100 can be used, but it can also be somewhat fickle. I am guessing that it has to do with the original oil and the BD process. I use B100 in my workshop and a nozzle heater was recommended to help with cold starts since my shop is not heated when I’m not using it. I have not purchased one yet, but found that when the weather is really cold(teens and single digits at night)that using a mixture of ~25% Kerosene helps. I would like to try the nozzle heater, but it is just a matter of having too many other projects going at the same time. I have also never noticed any buildup on my electrodes. Maybe you are burning too rich? The others here are much better than I at addressing those issues. Good luck and please post your results. Many people are considering using B100 for heating, but cannot find any firsthand information. Most of what is read is from “experts” that wouldn’t know a furnace from a blowdryer and who have never tried it for heating.