slabadie wrote:The manufacturer said that it is possible to get it to run 24 hours a day if I keep feeding coal every 3 hours, which mean I can't leave the house or sleep at night.
Are you sure about that? I've seen a lot of hand fired boilers in my life and the only way they differ from a standard hand fired stove is they heat water. From the PDF That particular one looks like one a customer of mine had for a few decades and she was nuts, e.g if it didn't work I'd of known about it. You should be able to get a 12 hour burn out of it and if that is not possible then I'd be less than happy myself.
My guess is there is problem between the coal bin and the shovel.
Took that from the oft quoted problem between the chair and keyboard for computer issues.
I wouldn't give up yet, first thing to do is get it out of your mind that you have lemon and approach it with a fresh start. Try using pea coal if you're using chestnut. How big is the firebox? I'm guessing that you're overfiring it, you're using an excessive amount of coal and all your heat is going out the chimney. You don't need a huge ball of fire to keep it going, it should be just idling along.with barely an flame coming off the coal.
I now the one my customer had was pretty complicated and you really needed to know what you were doing.