CTD500C-O
U.S. Boiler Company · Commercial Boiler
ENERGY STAR CertifiedCommercial Boilers →
Thermal Efficiency
97%
Input Rate
500MBTU/hr
Turndown Ratio
10.00
Application
Outdoor
U.S. Boiler Company CTD500C-O: thermal eff 97%, around the middle of the range for commercial boilers (category median 96.5%).
Where this model sits
Input500MBTU/hr
300median 7502500
Thermal Eff97%
94median 96.598.7
The U.S. Boiler Company CTD500C-O is a 500 MBTU/hr commercial boiler. At 97 % it ranks around the middle of the 386 certified commercial boilers models. Among similar-sized commercial boilers (within 10% of its size), it is less efficient than the peer median of 97 %.
Specifications
| Performance | |
|---|---|
| Thermal Efficiency | 97% |
| Full-Load Input Rate | 500MBTU/hr |
| Turndown Ratio | 10.00 |
| Configuration | |
| Application | Outdoor |
| Control Type | Multi-stage |
| Model Name | Citadel |
| Identifiers | |
| Model Number | CTD500C-O |
| ENERGY STAR ID | ES_1141425_CTD500C-O_05222026010201_10218465723 |
| Partner | Thermal Solutions Products LLC |
| Date Qualified | 2026-08-04 |
| Available From | 2025-08-01 |
| Markets | United States, Canada |
Documentation
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