The following outdoor hydronic heaters (wood-fired boilers) are U.S. Environmental Protection Agency (EPA) Phase 2 "white tag" qualified and their manufacturer(s) have submitted compliance certifications to the Massachusetts Department of Environmental Protection (MassDEP) as required by state regulation. Note: EPA "white tag" qualification is good for five years and must be renewed.

Only those units that appear on this list may legally be sold and installed for use in Massachusetts. Last updated in June 2015.


Central Boiler Inc. - 20502 160th Street, Greenbush, MN 56726 - 800-248-4681

Models: Classic Edge 350, Classic Edde 550, E-Classic 1400, E-Classic 1450, E-Classic 2400, E-Classic 3200, E-Classic 3250. Maxim M255 P, Maxim M255 PE


Dectra Corp. - 3425 33rd Avenue NE, Minneapolis, MN 55418  - 612-781-4236

Models: GARN WHS 1500 (indoor unit certified for outdoor use), GARN WHS 2000


Earth Manufacturing LLC - Box 310, Mountain Grove, MO 65711 - 417-926-4136 

Model: Klear Sky 400


Greentech Manufacturing Inc. - 2716 Crescent Drive, International Falls, MN 56649 - 866-361-7355

Model: Crown Royal Stove RS7400E


Hardy Manufacturing Co. Inc. - 12345 Road 505, Philadelphia, MS 39350 - 601-656-5866

Models: Klean Burn KB125, Klean Burn KBP165, Klean Burn KBP270 (currently certified for burning wood pellets only)


Hawken Energy Inc. - 1064 Industrial Park Drive, Shelby, MI 49455 - 888-564-2876

Model: GX10


Heatmor Inc. - 105 Industrial Park Court NE, Warroad, MN 56763 - 800-834-7552

Models: 200 SSP, 200 SSR II, 200X, 350X


Mahoning Outdoor Furnaces - 208 Whiskey Run Road, Mahaffey, PA 15757 - 800-692-5200

Model: Mahoning Skye Series V


Northwest Manufacturing Inc. - 600 Polk Avenue SW, Red Lake Falls, MN 56750 - 800-932-3629

Models: WoodMaster FlexFuel 30 KW, WoodMaster FlexFuel 60 KW


Piney Manufacturing Ltd. - Box 130, Piney, MB R0A 1K0, Canada - 204-423-2367

Models: Portage & Main Optimizer 250, Portage & Main Enviro Chip 500


Polar Furnace Manufacturing Inc. - Box 159, Sperling, MB R0G 2M0, Canada - 204-626-3485

Models: G2, G3


Pro-Fab Industries Inc. - Box 12, Arborg, MB R0C 0A0, Canada - 888-933-4440

Models: Empyre Elite XT 200, Empyre Pro Series 200, Empyre Pro Series 400


SteelTech / HeatMaster - 445 George Avenue, Box 158, Winkler, MB R6W 4A5, Canada - 204-325-9792

Models: HeatMasterSS G100, HeatMasterSS G200, HeatMasterSS G400