| GWGriswold Water Systems | Corona | CA | — | ◇ UNVERIFIED |
| GMGroup Manufacturing Services INC | Rancho Cordova | CA | — | ◇ UNVERIFIED |
| GMGroup Mfg Services, Inc-rancho Cordova Division | Rancho Cordova | CA | — | ◇ UNVERIFIED |
| HIHaakon Industries | Cheney | WA | — | ◇ UNVERIFIED |
| HSHarman Stove Mfg Halifax | Halifax | PA | — | ◇ UNVERIFIED |
| HCHarsco Corp/east Stroudsburg Plt | East Stroudsburg | PA | — | ◇ UNVERIFIED |
| HIHarsco Industrial Hammco, LLC | Owasso | OK | — | ◇ UNVERIFIED |
| HIHaseltine Industrial Engravers INC | Mountain View | CA | — | ◇ UNVERIFIED |
| HHHastings Hvac INC | Hastings | NE | — | ◇ UNVERIFIED |
| HBHauck Burner Mfg Cleona | Cleona | PA | — | ◇ UNVERIFIED |
| HMHauck Mfg Co/lebanon Plt | Lebanon | PA | — | ◇ UNVERIFIED |
| HHHearth - Home Technologies LLC | Lake City | MN | — | ◇ UNVERIFIED |
| HHHearthside Hearth & Home | Hixson | TN | — | ◇ UNVERIFIED |
| HWHearth Works Fireplace Center, INC | North Reading | MA | — | ◇ UNVERIFIED |
| HCHeateflex Corporation | Arcadia | CA | — | ◇ UNVERIFIED |
| HTHeath Tecna INC | Bellingham | WA | — | ◇ UNVERIFIED |
| HTHeat Tech | Gridley | CA | — | ◇ UNVERIFIED |
| HTHeat Timer CORP | Fairfield | NJ | — | ◇ UNVERIFIED |
| HTHeat Transfer Equipment CO. | Tulsa | OK | — | ◇ UNVERIFIED |
| HTHeat Transfer Equipment Company INC | Half Moon Bay | CA | — | ◇ UNVERIFIED |
| HCHeliodyne Corporation | Richmond | CA | — | ◇ UNVERIFIED |
| HWHicks Waterstoves and Solar Systems, INC. | Mount Airy | NC | — | ◇ UNVERIFIED |
| HMHi-tech Metal Fabrication | Anaheim | CA | — | ◇ UNVERIFIED |
| HBHolman Boiler Works | San Antonio | TX | — | ◇ UNVERIFIED |
| HGHouston Global Heat Transfer LLC | Humble | TX | — | ◇ UNVERIFIED |
| HEHoward's Engineering | Pico Rivera | CA | — | ◇ UNVERIFIED |
| HCHtp Comfort Solutions LLC | East Freetown | MA | — | ◇ UNVERIFIED |
| HSHugo's Specialties INC | Baldwin Park | CA | — | ◇ UNVERIFIED |
| HMHussong Manufacturing CO INC | Lakefield | MN | — | ◇ UNVERIFIED |
| HCHydac Cooling Systems (denver, Nc) | Denver | NC | — | ◇ UNVERIFIED |
| HIHydrodyne, INC. | Massillon | OH | — | ◇ UNVERIFIED |
| HCHydro-temp CORP | Pocahontas | AR | — | ◇ UNVERIFIED |
| ISIndependent Stove | Grants Pass | OR | — | ◇ UNVERIFIED |
| IHIndiana Heat Transfer CORP. | Plymouth | IN | — | ◇ UNVERIFIED |
| IDIndustrial Dynamics INC. LLC Dba Filtec | Torrance | CA | — | ◇ UNVERIFIED |
| IMIndustrial Manufacturing Solutions, LLC | Jennings | OK | — | ◇ UNVERIFIED |
| ILInfratech, LLC | (Gardena area) | CA | — | ◇ UNVERIFIED |
| IMInman Marine CORP Dba Imco | San Dimas | CA | — | ◇ UNVERIFIED |
| ILInspired Light LLC | Corvallis | OR | — | ◇ UNVERIFIED |
| IEIntegrated Energy Technologies (iet), INC. | Chula Vista | CA | — | ◇ UNVERIFIED |
| ICIntek Corporation | Union | MO | — | ◇ UNVERIFIED |
| IIInternational Innovations, INC. | Barre | VT | — | ◇ UNVERIFIED |
| IIIsotherm, INC. | Arlington | TX | — | ◇ UNVERIFIED |
| JMJ & M Manufacturing INC | Cotati | CA | — | ◇ UNVERIFIED |
| JCJohnson Controls | Wichita | KS | — | ◇ UNVERIFIED |
| JCJohnson Controls INC | Largo | FL | — | ◇ UNVERIFIED |
| JBJohnson's Boiler & Control INC | Fresno | CA | — | ◇ UNVERIFIED |
 JRJ Manufacturing, LLC | Pasadena | MD | — | ◇ UNVERIFIED |
| KRKc Radiators | N Hollywood | CA | — | ◇ UNVERIFIED |
| KKelvion (cimarron) | Catoosa | OK | — | ◇ UNVERIFIED |
| KKelvion (keystone) | Catoosa | OK | — | ◇ UNVERIFIED |
| KBKewanee Boiler Mfg LLC | Kewanee | IL | — | ◇ UNVERIFIED |
| KFKidd Fireplace | San Leandro | CA | — | ◇ UNVERIFIED |
| KEK-jack Engineering CO INC | Gardena | CA | — | ◇ UNVERIFIED |
| KHKoch Heat Transfer CO LP | Houston | TX | — | ◇ UNVERIFIED |
| LIL2f INC | Fremont | CA | — | ◇ UNVERIFIED |
| LFLakeside Fireplace & Stove | Walker | MN | — | ◇ UNVERIFIED |
| L2Lakeville 2 Hearth and Home | Lakeville | MN | — | ◇ UNVERIFIED |
| LMLamppa Manufacturing INC | Tower | MN | — | ◇ UNVERIFIED |
| LRLam Research, Balazs | Fremont | CA | — | ◇ UNVERIFIED |
| LBLawrence Brothers INC. Plant 2 | Rock Falls | IL | — | ◇ UNVERIFIED |
| LRLba Realty | Hayward | CA | — | ◇ UNVERIFIED |
| LBL. B. White Company, INC. | Onalaska | WI | — | ◇ UNVERIFIED |
| LRLkq Roseville (heatex Radiator Manufacturing Plant) | Roseville | MI | — | ◇ UNVERIFIED |
| LLL & L Industries, INC. | White | GA | — | ◇ UNVERIFIED |
| LMLor-van Mfg LLC | Santa Clara | CA | — | ◇ UNVERIFIED |
| LHLyons Human Resources, INC. | Russellville | AL | — | ◇ UNVERIFIED |
| MHMac Heaters, INC. | Bismarck | ND | — | ◇ UNVERIFIED |
| MIMake It Right-solar, INC | New Orleans | LA | — | ◇ UNVERIFIED |
| MTManchester Tank and Equipment | Petersburg | VA | — | ◇ UNVERIFIED |
| MTManchester Tank Financial INC | Franklin | TN | — | ◇ UNVERIFIED |
| MEMangold Engineering INC | Pomona | CA | — | ◇ UNVERIFIED |
| MSMarek Smiech | Santa Clara | CA | — | ◇ UNVERIFIED |
| MSMarlyn Sheet Metal, INC. | Clayton | NJ | — | ◇ UNVERIFIED |
| MWMary Wells Junior High School | Southbridge | MA | — | ◇ UNVERIFIED |
| MHMaxson Holding Company LLC Dba Acucraft | Big Lake | MN | — | ◇ UNVERIFIED |
| MHMaxson Holding Company LLC Dba Acucraft | Big Lake | MN | — | ◇ UNVERIFIED |
| MMMcdonnell & Miller Itt | Chicago | IL | — | ◇ UNVERIFIED |
| MKMc Kenna Boiler Wks INC | Los Angeles | CA | — | ◇ UNVERIFIED |
| MSMechanical Systems INC | Dundas | MN | — | ◇ UNVERIFIED |
| MSMechanical Systems INC | Benson | MN | — | ◇ UNVERIFIED |
| MBMercedes Benz of Walnut Creek | Walnut Creek | CA | — | ◇ UNVERIFIED |
| MSMeridian Sheet Metal, INC. | Oklahoma City | OK | — | ◇ UNVERIFIED |
| MIMestek INC Dadanco | Westfield | MA | — | ◇ UNVERIFIED |
| MIMestek Incorporated | Farmville | NC | — | ◇ UNVERIFIED |
| MIMestek INC South Bldg | Westfield | MA | — | ◇ UNVERIFIED |
| MMetromatic | Medford | MA | — | ◇ UNVERIFIED |
| MLMG Louisiana LLC | Pineville | LA | — | ◇ UNVERIFIED |
| MCMicro Cooling Concepts, INC. | Huntington Beach | CA | — | ◇ UNVERIFIED |
| MMMina Metals CO INC | South San Francisco | CA | — | ◇ UNVERIFIED |
| MAMiura America CO LTD | Irwindale | CA | — | ◇ UNVERIFIED |
| MAMiura America CO LTD | Rockmart | GA | — | ◇ UNVERIFIED |
| MSMkm Sarasota LLC | Sarasota | FL | — | ◇ UNVERIFIED |
| MCModel Cleaners/charleroi | Charleroi | PA | — | ◇ UNVERIFIED |
| MMModine Mfg CO | Racine | WI | — | ◇ UNVERIFIED |
| MTModine Transferencia De Calor Sa De Cv | Laredo | TX | — | ◇ UNVERIFIED |
| MMModular Metal Fabricators INC | Moreno Valley | CA | — | ◇ UNVERIFIED |
| MHMonessen Hearth Systems | Athens | AL | — | ◇ UNVERIFIED |
| MPMonolithic Power Systems INC | San Jose | CA | — | ◇ UNVERIFIED |
| MMMonterey Mechanical CO Dba Contra Costa Metal Fabricators | Concord | CA | — | ◇ UNVERIFIED |
