Restarting coal fire after being unattended

If a fire is not attended to and there is unbunt coal in furnace do you have to clean all the unburnt coal that was not burned out before restarting?
Or can you start a new fire on top of coal that did not burn?

That's what worked for me. I'd just clear the ash out a little first and start over. But don't go by me-I'm new around here-and I'm just gaining enough knowledge to become dangerous.

It usually is easier to shovel out the old partially burnt coal and start from clean grates. Then once you have established a good hot coal fire, toss the 'old coal' on the fire,, it will have the best possible opportunity to burn on the top/center of the fresh fire.. Sometimes the unburnt remaining coal won't burn very well on the bottom of the fire, and these pieces of unburnt coal can be difficult to get ground up by the grates and into the ashpan.. if too much of this large, unburnable stuff accumulates, then getting enough air to the fire can become a problem. As well as jamming in the grate openings while shaking.

Once you decide to burn for several days or weeks, or for the season,, load your firebox to the top of the firebrick,, the coal will burn better in a deep coal bed, more completely, and it will be easier to control, and you can even slow the burn rate more with a deep fire than with a shallow fire..

If I were to build a hand-fed firebox, now that I've made several mistakes and struggled with poor designs,, I'd make the firebox at least as deep as it is square,, so it would be probably 16"x16"x 20" deep.. with all the bottom of the fire being shaker grates.. Firebrick lined. If I were to make it round, it would have the rough dimesions of a 5 gallon bucket..

Hope this helps.. Greg L

If you catch the fire while still hot, and some of the coal is still hot, I used to use two 1/4 split pieces of firewood, one in each hand, scrape the hot coals into a row between the pieces and make a channel for the fire to stay hot and be rebuilt in.. this usually worked for me in my 'Big Bertha' when it was still being burnt as a hand feed boiler.

Greg L

I agree. If the fire is dead...clean it out & start from scratch for a much easier relight. (I always dig unburnt coal out of the ashes to re burn on a fresh fire. kinda feel like I'm digging out 1/2 smoked cigarette butts when I was a desperate smoker some mornings but...."waste not want not"! )

Do it once - do it right the first time!
Clean it out and you get the highest probability of success.

See, I told you I was becoming dangerous. Listen to the other guys.

A soil sifter works to get the re-burnables out after a miss-fire!

Lots less aggravation if you start clean. You really can't get old coal to burn underneath of a new wood fire until which time the entire fire becomes one & is hot with wood coals. My .02 cents worth

I agree with others. Clean it out , and start from scratch. That is what I would recommend to anyone who is new to starting coal fires. On the other hand , I start the coal fire in my garage stove several times through out the winter. This is what I do. Instead of emptying the entire firebox , which can be quite messy , I shake it down good. Then , take what's left in the firebox and push it off to the sides with the poker. Do this till you get down to the grates , or at least close to the grates. Now your starting a much smaller fire. Use charcoal size pieces of wood. As the fire gets going , use new coal over the fire. Once the new coal is going , even out the firebox with the stuff pushed off to the sides. Before you know it , the whole bed of coals (new & old) will be glowing orange.