| CCChentronics CORP | Norwich | NY | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| DSDetroit Stoker CO | Monroe | MI | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| EIEcr International INC | Dunkirk | NY | Machinery Manufacturing333414 | 100-499 | ◐ LIKELY ACTIVE |
| ECEmpire Comfort Systems | Belleville | IL | Chemical Manufacturing325211 | 100-499 | ◐ LIKELY ACTIVE |
| IIIea INC | Kenosha | WI | Machinery Manufacturing333414 | 100-499 | ◐ LIKELY ACTIVE |
| IDInfrared Dynamics | Yorba Linda | CA | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| IBInternational Baler | Jacksonville | FL | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| MCMaxon CORP | Muncie | IN | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| MUMenk USA | Sterling | IL | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
Modine Manufacturing Company | Lawrenceburg | TN | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| PFPower Flame Incorporated | Parsons | KS | Machinery Manufacturing333414 | 100-499 | ◐ LIKELY ACTIVE |
Rheem Manufacturing Company | Fort Smith | AR | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
Rheem Manufacturing Water Heater Div | Montgomery | AL | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| TCThe Cleaver-brooks Company, INC. | Thomasville | GA | Fabricated Metal Product Manufacturing332410 | — | ◐ LIKELY ACTIVE |
| TPThermo Products, LLC. | Denton | NC | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| UBUS Boiler INC | Lancaster | PA | Fabricated Metal Product Manufacturing332410 | 100-499 | ◐ LIKELY ACTIVE |
| WFWilliams Furnace CO | Colton | CA | Machinery Manufacturing333414 | 100-499 | ◐ LIKELY ACTIVE |
| HIHayward-comfortzone INC | Nashville | TN | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| HHHearth & Home Technologies of Lake City | Lake City | MN | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| ICIndustrial Combustion LLC | Monroe | WI | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| MMModine Mfg., CO. | South Kingstown | RI | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| QQuadra-fire | Colville | WA | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| SIState Industries INC | Ashland City | TN | Machinery Manufacturing333248 | — | ◐ LIKELY ACTIVE |
| BCBurnham CORP | Lancaster | PA | Machinery Manufacturing333414 | — | ◇ UNVERIFIED |
| 9S92084 - Stepp Manufacturing CO INC | North Branch | MN | Machinery Manufacturing333120 | 20-99 | ◐ LIKELY ACTIVE |
Gas-fired Products, INC | Charlotte | NC | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
Heat Energy Systems Company, INC. | Springfield | TN | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| JWJen-ter Wire & Element, INC. | Fox Lake | WI | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| LTLock-ridge Tool Company | Pomona | CA | Machinery Manufacturing333414 | — | ◇ UNVERIFIED |
| AIAerco International INC | Blauvelt | NY | Machinery Manufacturing333318 | 100-499 | ◐ LIKELY ACTIVE |
| ASAlfa-laval Separation INC | Chesapeake | VA | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| AHAqua Hot Heating Systems | Frederick | CO | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| BTBeckett Thermal Solutions Strongsville | Strongsville | OH | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| BFBoyertown Foundry Company | New Berlinville | PA | Primary Metal Manufacturing331511 | 20-99 | ◐ LIKELY ACTIVE |
| CBCleaver Brooks | Monroe | WI | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| DPDon Park USA (LP) | Conley | GA | Fabricated Metal Product Manufacturing332322 | 20-99 | ◐ LIKELY ACTIVE |
| DCDutro Company | Logan | UT | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| ECEmpire Comfort Systems, INC. | Belleville | IL | Machinery Manufacturing333414 | 100-499 | ◐ LIKELY ACTIVE |
| FNFives North American Combustion, Incorporated (1318173445) | Cleveland | OH | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| FRFng Recycling CORP | Compton | CA | Fabricated Metal Product Manufacturing332321 | — | ◐ LIKELY ACTIVE |
| FTFulton Thermal CORP. | Pulaski | NY | Fabricated Metal Product Manufacturing332410 | — | ◐ LIKELY ACTIVE |
| HSHarman Stove Mfg Halifax | Halifax | PA | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| HMHeatmor Manufacturing | Warroad | MN | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| KEKing Electrical Manufacturing Co | Seattle | WA | Machinery Manufacturing333414 | 100-499 | ◐ LIKELY ACTIVE |
| OGOutdoor GreatRoom Company | Lakeville | MN | Machinery Manufacturing333414 | 20-99 | ◐ LIKELY ACTIVE |
| PHProcess Heating Company, INC. | Seattle | WA | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |
| RMRam Mechanical Inc | Ceres | CA | Fabricated Metal Product Manufacturing332322 | 20-99 | ◐ LIKELY ACTIVE |
| RIRasmussen Iron Wks | Whittier | CA | Fabricated Metal Product Manufacturing332510 | 20-99 | ◐ LIKELY ACTIVE |
| RRRefrigeration Research INC | Brighton | MI | Fabricated Metal Product Manufacturing332420 | 20-99 | ◐ LIKELY ACTIVE |
| SISunearth, INC. | Fontana | CA | Machinery Manufacturing333414 | — | ◐ LIKELY ACTIVE |