Home-Built Furnace Still Burning After Nearly 50 Years

Home-Built Furnace Still Burning After Nearly 50 Years FARM SHOW had just wrapped up its seventh year when founder Harold Johnson stopped by Darwin Reyne’s farm. He was there to see Reyne’s home-built wood-burning hot water furnace, which had been built five years earlier, not long after Harold started FARM SHOW. Harold was suitably impressed and wrote it up in Vol. 8, No. 1. When Reyne recently contacted FARM SHOW, we decided it was time for an update. “The furnace is still operating,” says Reyne. “My son lives on the farm now. The only thing we’ve done is to replace the grate, which was made out of an old cast-iron heating register.” The furnace measures 30 in. long, 30 in. wide, and 36 in. high. A water jacket holding about 30 gal. of water is wrapped around the 24-in. square firebox. The firebox was fabricated from 3/16-in. steel plate, with the lower half lined with firebrick. About 3 1/2 in. of insulation is wrapped around the water jacket. Reyne designed the furnace with an ash pan for easy cleaning and large enough to hold a week’s worth of ashes. “I built it in 1979 when fuel prices shot up,” says Reyne. “I had an oil-fired furnace that heated water for baseboard radiators.” Reyne tied his new furnace into the existing system using the oil burner’s water pump. He quickly found the wood furnace provided even better heat, warming the four-bedroom house and basement. Fully loaded, it held a fire for 10 to 12 hrs. “We only used the oil burner if we were going to be gone for an extended period or in the spring and fall, when we just needed a little heat,” he says. The only downside he found was that the pump must run continuously while the wood is burning to prevent overheating. A 210 F pop-off valve on top of the water jacket, with a temperature gauge, serves as a safety. “I had to override the automatic controls on the oil burner,” recalls Reyne. A few years after Harold’s visit, Reyne sold the oil burner to a neighbor and replaced it with a supplemental heater of his own design. “I made an electric unit out of 2 ft. of auger tubing and suspended it from the ceiling,” says Reyne. “I put three 45-watt heating elements in it and plumbed it into the waterline from the furnace. When the water temperature drops, the thermostat kicks in the electric unit. It only holds about 2 gal. of water, but that’s enough. It takes no time at all to heat up.” When he built his furnace, Reyne estimated the materials cost at about $275. In the early 1980s, he estimated it saved him up to $1,000 a year. Even without fuel oil price fluctuations, that adds up to a nice ROI. With the ash borer taking its toll today, Reyne notes that he and his son have plenty of free wood to work with. “He burns mostly ash wood now,” says Reyne. “It’s plentiful.” Contact: FARM SHOW Followup, Darwin Reyne, 200 Oak Dr., Luverne, Minn. 56156 (ph 507-449-7856).

To read the rest of this story, download this issue below or click here to register with your account number.