coal feeding problems.

I have an old Stokermatic....Not sure of the model, It has a bin you put the coal in and it feeds the fire from underneath ( I know....I'm not too techinical!) The problem is that it keeps feeding the coal in, and it builds up without burning it all. My husband is pretty handy but can't figure out what the problem is. Can anyone offer some assistance here? Thanks!
Marlene

Does your feeder have an adjustment screw on the feeder motor? If so turn it back a few turns and see how much ash you have at the end of the stoker plate. Most stoves call for a half inch to an inch of ash.

Does your stoker look like this one?

Yes, that's what it looks like! My husband cleaned it out really good and it seems to be working for now.

a good cleaning can help, however one of two problems may be at the root of this. it is likely that the feed rate of coal is too high for the air; either decrease the feedrate or increase the air. another issue that can cause a lot of headaches is a loose feed belt; you end up adjusting the air for the coal feed, but the belt is slipping, as the stoker runs for long periods such as it would on cold days or nights, the belt warms up and "sticks" better to the pulleys, this causes the feedrate of the coal to increase and now you don't have enough air to burn all the coal being fed, thus the coalfire builds excessively. the fix, of course, is to have a belt that is newer, free from grease and oil, and fits snugly but not excessively tight.

If you have any more problems take some pictures (if possible) of the fire while stoking and exactly how much buildup you're getting.

If it worked after cleaning, the problem on some stokermatics is the air vents in the bowl get plugged. It matters what the size and spread of the vents in the bowl are. It only happened to me when I first hooked up a large warrior 150. The stove wasn't getting any air through the bowl and the box was filling with coal. If you do have to adjust your feed rate you have to buy a different sized pulley to attach to the feed motor. Other than that if you adjust the air vents as high as they will go it should run fine.