| ENERGY STAR Partner |
| The Marley-Wylain Company |
The Marley-Wylain Company |
| Brand Name |
| Williamson-Thermoflo |
Williamson-Thermoflo |
| Model Name |
| OWB |
OWB |
| Model Number |
| OWB-4-T-S2-D |
OWT-4-T-S2-D |
| Type |
| Boiler |
Boiler |
| Fuel Type |
| Oil |
Oil |
| Efficiency (AFUE) |
| 87 |
87 |
| Date Available On Market |
| October 15, 2014 |
October 15, 2014 |
| Date Qualified |
| November 8, 2021 |
November 8, 2021 |
| Markets |
| United States |
United States |
| CB Model Identifier |
| ES_1090273_OWB-4-T-S2-D_03072018200725_8405711 |
ES_1090273_OWT-4-T-S2-D_03072018200728_4741214 |
| Can Integrate Hot Water Heating |
| No |
Yes |
| Product Category |
| Boilers |
Boilers |
| Date Certified |
| November 8, 2021 |
November 8, 2021 |
| Meets ENERGY STAR Most Efficient 2024 Criteria |
| No |
No |
