U.S. Environmental Protection Agency (EPA) regulation and certification of new residential outdoor hydronic heaters changed on January 1, 2016. As a result, only those MassDEP-certified units listed below are currently legal to sell and install in Massachusetts. Units not listed below but certified by MassDEP and legally installed by Massachusetts homeowners before the end of 2015 are unaffected and may continue operating.

Please also note that the MassDEP outdoor hydronic heater regulation at 310 CMR 7.26(50) – including manufacturer compliance certification, stack height and installation setback requirements – remains in full effect until further notice.

Questions? Contact Marc Cohen: 617-292-5873 or marc.cohen@state.ma.us

Only those units that appear on this list may legally be sold and installed for use in Massachusetts. Last updated in October 2016.


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

Models: Classic Edge 350, Classic Edge 550, Classic Edge 750, E-Classic 1450, 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


Econoburn Boilers
2 Central Avenue
Brocton, NY 14716 
716-792-2094

Model: EBW200-170 (certified for burning cordwood only)


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, 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

Model: WoodMaster CleanFire 400


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

Models: 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 400


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

Models: HeatMasterSS G100, HeatMasterSS G200, HeatMasterSS G400