Log in

View Full Version : Dealing with "Old Smokey" a coal furnace


SLCamp
Jan 5, 2008, 06:05 PM
Does anyone out there know about coal furnaces? Sounds silly but you would not believe how hard it is to get help with one of these monsters. By working and taking the
Thing apart several times my daughter finally was able to install a new gear box and motor but in the meantime the thermostat seems to have stopped working and the clock is only
Running the stoker on hold fire. We put in a new mercury switch type and it is level so my
Next guess is something else on the furnace.
On the furnace bonnet there are 2 boxes, one is the limit control but I have no idea what the other one is except that the wire that comes out of it goes into the same place that
The thermostat wires go, and on the front of this box is a little switch that say automatic or
Manual. Does this have to do with the thermostat?
Thanks for any help anyone can give.
SLCamp

hvac1000
Jan 5, 2008, 06:18 PM
One is a limit and the other is for the coal stoker. The thermostat passes through the switch and the switch tells the stoker to add coal. It also acts as a stop so too much coal is not added. It has been 30 years since I worked on one so I do not have much onfo to offer. I used to keep all the different stoker shear keys on the truck as a memento.