Connecticut Limited Heating Cooling License (D-3 and D-4) Connecticut’s heating and cooling licensing framework recently tightened efficiency standards and refrigerant handling protocols for D-3 and D-4 technicians. Current exams emphasize EPA Section 608 compliance, modern heat pump diagnostics, and updated building codes reflecting state sustainability mandates. Staying current with these shifts is essential? examiners now weight system commissioning and low-GWP refrigerant practices more heavily than in previous years.
| Exam Name | Connecticut Limited Heating Cooling License (D-3 and D-4) |
| Format | PDF & Practice Test Engine |
| Target Year | 2026 Updated |
| Features | 100% Verified Q&As |
