Cold-air check damper open about one-eighth to one-third distance of the opening.
Smoke-pipe damper about one-half closed.
A little experiment with the draft will usually tell the operator the best way of leaving these dampers.
It will be found in the morning that the entire charge of coal is well burned or partly coked.
The coked fuel, or that which sticks together in a mass, should be broken up by the poker and more added generally as by rules given in other sections.
It must always be remembered that the soft coals mined in different parts of the country have widely varying heat-making capacities. To obtain satisfactory results brands must be selected which have an established reputation for excelling results in small boilers.
For Burning Coke.
—It is best to keep the pot full of fuel—keeping a large body of coke under a low fire rather than a little fuel under a strong fire.
It must be remembered that coke makes a very “hot fire” because the coke is free-burning. Care should be taken not to leave drafts on too long in boilers not having regulators.
Coke burns best for house-heating purposes with less draft than is required for coal, therefore to keep a low fire the ash-pit draft damper should be kept closed, and the smoke-pipe damper almost entirely closed. The regulator (when used) can be set to keep the dampers about as here advised. Coke is practically smokeless and its quick-burning character makes a cut-off damper in the smoke pipe (which will stay fixed as it may be set) quite necessary.