To heat only our homes DHW (not including a hot tub) we are going through about 13.8 to 14.4 lbs. of coal per day on average in our AHS S130 (I add coal every 13-14 days and then back calculate for the average usage over that time period). Our homes hot water comes directly from the boilers DHW coil, via a 3-way thermal mixing valve (Taco 5003 series). There is no direct or indirect hot water tank (we have an electric hot water tank, but it is shut off and valved off).
During the summer there is no circulation of boiler water with our set-up, with the sole exception of when (or if) the boiler trips the dump zone (which does not happen very often at all with the dump zone aquastat set to trip at 215 degrees. I've only directly observed it to happen once this summer). The only water that moves during the summer is the water traversing its course through the DHW coil and then off to the users in the home (sinks, showers, dish washer, clothes washer).
After the blower fan shuts off at 180 degrees, our boiler seems to subsequently over-shoot to a temperature of about 212-213 degrees and then reach a comfortable equilibrium between heat being created within and heat being radiated away to the surrounding air, thus remaining comfortably close to but not tripping the dump zone circulator. When my dump zone aquastat was set at 210 degrees the boiler dumped rather often, but at 215 degrees it does so exceedingly rarely. This fine line of equilibrium seems to be a key secret to using hardly any coal at all.
With a hot tub, 30 lbs. of coal per day may be about right.