My brother and I are thinking of burning coal in his Heatmoor boiler mostly in colder weather due to have a limited amount of wood ready this year. We have read online about mixing wood and coal, but this doesn't seem right to me. We can get coal somewhat locally for around $80 a ton. We have burned lots of wood in this boiler a long with other forced air furnaces and stoves but never coal. I would appreciate any advice on the subject thanks.