| ENERGY STAR Partner |
| Thermal Solutions Products LLC |
U.S. Boiler Company, LLC |
| Brand Name |
| Burnham by U.S. Boiler |
Burnham by U.S. Boiler |
| Model Name |
| Citadel |
K2FT |
| Model Number |
| CTD650 |
ASPN-399 |
| Full Load Input Rate (kBtu/hr) |
| 650 |
399 |
| Thermal Efficiency (%) |
| 97 |
95 |
| Turndown Ratio |
| 10 |
10 |
| Control Type |
| Multi-stage |
Multi-stage |
| Application |
| Indoor |
Indoor |
| Date Available On Market |
| April 24, 2023 |
August 1, 2017 |
| Date Qualified |
| February 22, 2024 |
April 10, 2018 |
| Markets |
| United States, Canada |
United States, Canada |
| CB Model Identifier |
| ES_23449_CTD650_05112023171729_1283540 |
ES_23449_ASPN-399_04102018180448_9841030 |
| Product Category |
| Commercial Boilers |
Commercial Boilers |
| Type |
| Commercial Boilers |
Commercial Boilers |
| Date Certified |
| February 22, 2024 |
April 10, 2018 |
| Meets ENERGY STAR Most Efficient 2024 Criteria |
| No |
No |
