Classification 311
District of Columbia 311 — Master A/C & Refrigeration Mechanical Unlimited Exam Prep
Prep for the District of Columbia Master A/C & Refrigeration Mechanical Unlimited trade exam. Requirements vary by license, so confirm with the licensing board which exams you must pass.
Master A/C & Refrigeration Mechanical Unlimited question bank is being built
The 311 trade bank isn't published yet, so we're not charging for it. Join the waitlist for 311 and we'll email you the moment it's live.
Official resources
- DC Department of Licensing and Consumer Protection (DLCP), Board of Industrial Trades
- Official District of Columbia examination study guides
- PSI Services (exam administration)
ContractorPrepHQ is an independent study platform and is not affiliated with DC Department of Licensing and Consumer Protection (DLCP), Board of Industrial Trades or PSI Services. Verify current exam requirements with the licensing authority.