Coal, of course can be used in your stove. WESO, the manufacturer of this stove is located in Germany where wood burning is a rarity among coal users. Anthracite of the walnut size works best. I have been using the model HSK 225 C3-4 since 1986 seasonally providing all the needed heat in a 3-bedroom house off the coast of Maine. On the coldest days of winter I use approximately 40 pounds (A little less than a typical bag) per day. Your stove may be smaller than mine and therefore different rules may apply.
For your situation you may want to be sure that the proper inserts for coal burning have not been removed from the fire chamber as your stove has been exclusively utilized for wood burning. As to the operation of your stove, you should be able to duplicate what I am doing for years. During the spring and fall seasons you will be tending your stove once every 24 hours, probably in the morning. You will observe that you have steady heat during the day and night. During the coldest days in the winter you may find that you have to attend to your stove every 12 hours to get the kind of comfort you desire.
For somebody who has been using wood exclusively coal burning may be a bit tricky at the beginning. You start your stove with a usual hot wood fire. Once you have a red hot wood fire going (red glowing) add a two inch layer of coal and allow this to get as hot as the wood fire. At that point you add other layers of coal until the top of the coal is level with the top of the firebox. You will find that adding cold coal actually cools the firebox. If your room is optimally tempered, you may choose to reduce the air flow to the firebox at that time. If you like more heat, let the top layer heat up a little before reducing the air flow. You probably want to reduce the air flow to the lowest setting before going to bed. If you do nothing from this point on the fire will still be going 24 hours later. - This needs a little practice; but you will be extremely satisfied with the performance of your Weso stove.
At the 24 hour mark or earlier in the dead of winter, mostly in the morning, you will find that the stove has cooled down a bit. You may barely see glowing coal in the center. At this point do NOT shake the ashes! Instead, open the air vents and allow the maximal amount of air to flow. In about 20 or 30 minutes you will find you have reawakened a hot coal fire. This is the moment you vigorously shake the ashes out of the firebox. And a short while later you add new coal to the firebox as outlined above. By following this method you will have a steady fire going for weeks. And you will also find that the temperature in your room is steady and comfortable. This is a great bonus, finding your home comfortably tempered, when you come home from work.
The WESO stove in my experience is the best of all coal stoves on the market. I have mine going in the center of the house, heating the great room and the kitchen. The surrounding bedrooms are comfortably tempered for sleeping. It is the sole source of heat in the house.
Before you start though, make sure that the proper coal burning inserts have not been removed from your stove. Coal burning requires a much smaller firebox than what is used for wood. These inserts are available as WESO sells spare parts for existing stoves. The Company Name: Ceramic Radiant Heat, 603-364-6776 or e-mail them at firstname.lastname@example.org
. I have good experience with this company. I had to replace one single firebox insert component in over 20 years, a pretty good record.
Good Luck with your WESO stove,