Plumbing and HVAC rules in Maryland

What the state says about plumbing and heating and cooling work, with the page each rule comes from. It's a summary of the published rules, not legal advice, and your city or county can have rules of its own.

Checked September 23, 2026

Plumbing licensing

Plumbers in Maryland hold master, journeyperson or apprentice licenses from the State Board of Plumbing.^{1, 2, 3}

Heating and cooling licensing

Maryland's State Board of Heating, Ventilation, Air-Conditioning and Refrigeration Contractors licenses people who provide residential and commercial HVACR services.⁴

Plumbing and mechanical codes

Your local building department can tell you which plumbing and mechanical codes apply where you live.

Permits to replace a water heater, furnace or AC

Ask your local building department whether replacing a water heater, furnace or AC needs a permit where you live.

Backflow testing

If your home has a backflow preventer, your water utility can tell you whether it needs testing and who can test it.

Sources

What plumbing and HVAC work costs in Maryland

Published national ranges for plumbing, water heater, sewer, AC, heat pump and furnace jobs, and a planning estimate for your own job.

Plumbing, heating and cooling costs in Maryland

Contractors in Maryland

987 plumbers and heating and cooling contractors are listed in Maryland. 537 hold an active USDOT registration. Browse them by county, or ask for quotes and we'll pass your job to contractors near you.

Cite this page

“Plumbing and HVAC rules in Maryland.” PlumbingInformationSite.com, updated September 27, 2026. https://plumbinginformationsite.com/md/rules/