My 16 gal WJ bottler has 1 heater 4500 watts. I heat syrup in my finisher (2x6) to 205-210F+ then send it thru the filter press and into the bottler. If the filter press is still hot from filling a SS barrel, the temp in the WJ bottler will be at bottling temp in just a few minutes if not immediately. Once in the bottler, If I heated the WJ water first, it only takes 30-45 minutes. If the WJ water started cold maybe 2 hrs. Then if I don't finish bottling the contents I have 2 options. #1, I leave the unit hot (185-187F) and put my homemade insulated cover over it (made of 1" rigid foam) and it is ready to bottle when I return. #2. If I turn the heater element off, it can take 3-4 hrs to raise the temp to 185F, the more syrup in the bottler the longer it takes.
The beauty of a WJ bottler is that the t-stat maintains the perfect temperature once attained.
Mine is a Smoky Lake WJ bottler, I see they now offer a steam heated bottler, I suspect that would be faster (and it is lower cost) Also my friend has a SunRise WJ bottler with propane heat under it and 2 4500 watt elements. I think he said that holds 35 or 40 gal. I understand he uses the propane to heat the WJ faster (and the syrup), then the burner gets shut off and the electric does the rest. That might be the best of both worlds.
Dave Klish, I recently bought a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.