HeatMaster Furnaces G Series G4000 is a non-catalytic hydronic heater from HeatMaster Furnaces certified at 0 g/hr particulate emissions with 86% HHV efficiency and a 16,203–99,840 BTU/h output range.
General
Appliance type
hydronic-heater
Combustion technology
Non-Catalytic Stove
Certified fuel
Cord Wood
Covered model numbers
G Series G4000
Emissions
Emission rate
0 g/hr
Carbon monoxide
1.6 g/min
Efficiency
Efficiency (HHV)
86 %
Heat output
Heat output (low)
16203 BTU/h
Heat output (high)
99840 BTU/h
Firebox volume
8.5 cu ft
Certification
25C tax credit eligible (≥75% HHV)
Yes
2020 NSPS compliant
Yes
Currently in production
Yes
EPA certification number
43HH-20
What space does the HeatMaster Furnaces G Series G4000 suit?
The 8.5 cu ft firebox puts it in the large-home, overnight-burn
class.
Certified burning Cord Wood — the test fuel closest to real-world firewood.
Is the HeatMaster Furnaces G Series G4000 EPA certified?
Yes, the HeatMaster Furnaces G Series G4000 is on the EPA's current list of certified wood heaters (certification number 43HH-20) and meets the 2020 NSPS Step 2 emission limits.
What is the HeatMaster Furnaces G Series G4000's emission rate?
The HeatMaster Furnaces G Series G4000 is certified at 0 grams of particulates per hour (tested with cord wood). Real-world emissions depend heavily on fuel moisture and operation — the lab figure assumes seasoned fuel and correct air settings.
Does the HeatMaster Furnaces G Series G4000 qualify for a federal tax credit?
No — the federal 25C credit for biomass stoves was terminated for property placed in service after December 31, 2025. The HeatMaster Furnaces G Series G4000's certified efficiency is 86% HHV, which met the credit's ≥75% HHV threshold while it existed. State and local incentive programs may still apply — check your state energy office and air district.
