Who makes boilers for burning coal

Do you know of any manufacturers of coal-burning, add-on boilers which are designed especially for coal? I've seen several add-on wood boilers but I question how much research and engineering went into their manufacture. James H. Mearns Poughkeepsie, N.Y.

Add-on boilers, or coal stoves, are being built which allow a homeowner to use the anthracite-burning unit when he is home to tend it, thus taking advantage of the lower cost of the fuel. Then when the homeowner is away from the house for a time, he can fall back on the automatic feature of the oil.

It actually makes a very sensible combination, says a local coal dealer.

Shenandoah makes such a stove for a hot-water system which attaches to the oil boiler, I'M told. The address is Shenandoah Manufacturing Company, PO Box 839, Harrisonburg, Va. 22801.

Also, I understand another system is made by Fire Line Inc., 80 Portland Street, Fryeburg, Maine 04037. Called Fire Plate, it goes right next to the oil-fired boiler. All you do is turn a couple of valves and divert the water through the coal-fired system.

Why don't you get in touch with the company and ask about its system and others?

You could drop a line to the Cambridge Alternative Power Company, 299 Concord Avenue, Cambridge, Mass. 02138. The phone number is: (617) 547-0400. The firm also carries a line of multifuel furnaces: coal, wood, oil, etc.