Well the 520 has been cranking along for a month now, no outfires, plenty of heat in house and domestic water. I have gone thru about 1 1/2 ton in a month and the weather has not really been cold, I would say daytimes avaeraging mid 40 and nites just at freezing.
I am set at 4 teeth, the lowest it will go, 4 1/2 air. Baro set at .02 the lightest it will go. Temp is down as low as I can get it with my set up. running about 145 degrees. I am not sure what my timer is set at as it is old and I can not read the numbers on it, so I just left as it was when I bought it. It does run about 2-3 minutes, I think about every 20 minutes or so.
My pump is on teh return side at my furnance and the lines run appx 150 to teh furthest exchanger. Pump runs non stop, I did not want to have 150 of cold water dumping back into the tank and then having to put a delay on the fan to wait for hot water to circulate back to exchanger. Since water is circulating nonstop I did not put a loop on my main outside of furnance. I do have the high end closed cell pipe buried below frostline.
Does this seem like too much coal to be using?
Unit is great and will still save me $ over LP and electric. Plus wife is happy with heat in house, set at 70 now used to be 64 day and 60.