10-2

Colorado licenses and hiring a pro

Colorado plumbing license rules let a homeowner work on their own residence without one, as the statute is published, but rentals, commercial buildings and property built or remodeled for sale fall outside, and permits generally still apply.

Use this when: You are weighing doing a job yourself or about to hire someone for plumbing, electrical, well or heating work.
Done when: You know whether the job is yours under the rule, and any hire has given license and registration numbers and said who pulls the permit.
Who: You, then the licensed trade for the job

Written for this manual, last checked against sources November 4, 2026. Who wrote it

Old brick Montrose house with a teal roof, upper balcony and big cottonwood on a green summer lawn.

10-2.1 Can a homeowner do their own plumbing in Colorado?

On your own residence, the statute says no license is needed. As published, the exemption covers plumbing work on your own property or residence. It doesn't cover property for sale or resale by a building or remodeling business, commercial or industrial buildings, or rentals.

The exemption is about the license, not the permit. Permits come before work starts, and qualified applicants include homeowners working on their own homes. Mesa County's card says the same thing from its side: "Except for a residential homeowner, it is illegal to perform electrical and plumbing work except by those licensed to do so by the State of Colorado."

These statutes are read from a published copy. The state's plumbing pages and license lookup couldn't be opened for this manual, so confirm the current wording with the Department of Regulatory Agencies (DORA) before relying on it.

Tan and teal two-storey Montrose house with a round front porch, lavender and a short brick walk.

10-2.2 What about the water heater?

A December 2025 state notice answers this one directly. DORA's addendum of December 4, 2025 says homeowners may install or replace domestic water heaters themselves "as long as the home is not for sale, resale, a flip, or a rental property", and must still get a permit and inspection from the authority having jurisdiction.

You may also come across the DORA memo of December 3, 2025, which says water heaters must be installed by a licensed plumber working for a registered contractor. The addendum came a day later and speaks to homeowners directly, so this manual follows it for homeowners.

10-2.3 Who may do which job?

This table separates what sources state from what this manual advises. Local offices can add to it (§10-1).

**Table 10-2a** Jobs, rules and this manual's advice
Job	What sources state	This manual's advice
Plumbing on your own home	No license needed; permit before work	Yours if you know the work, with the permit
Plumbing on a rental	Exemption doesn't cover it	Licensed plumber
Water heater, own home	Homeowner may, with permit and inspection, if not for sale, flip or rental	Gas side and venting to a pro
Gas piping	Covered by the same permit and inspection statute	Licensed pro only
Electrical on your own home	No license if inspected, apart from maintenance or repair of existing facilities	Breaker and switch checks only
Well pump, for pay	Licensed pump installation contractor	Licensed contractor
Well pump, own well	Private pump installers exempt from licensing, still under construction rules	Ask the state or a licensed installer first
Cistern between wellhead and pressure tank	Only a licensed pump installation contractor	Licensed contractor

The electrical line is from the owner exemption, which adds that owners planning to sell, rent or open to the public take on licensing duties. The pump lines are 37-91-102, 37-91-106 and 37-91-109. Those last two pull in different directions on owner work, so this manual doesn't tell you that you may do it. We couldn't open the pages of the Colorado Division of Water Resources when this was last checked, so ask it directly.

10-2.4 What licenses exist?

The statutes name these. No one may work as a residential, journeyman or master plumber without a license. Plumbing contractors must register with the board, a master plumber must own or work full-time for the contractor, and apprentices register within 30 days. Electricians are master, journeyman or residential wireman, and contractors register too.

Heating is less clear. No source opened for this manual says outright whether Colorado has a state HVAC license. Mesa County's permit form asks for state numbers only from plumbers and electricians, and an HVAC city license only inside Grand Junction. That fits with there being none, but it doesn't prove it, so ask your local office what it requires of heating contractors.

10-2.5 How do you check someone before you hire them?

Ask for numbers, then check them with the office that will take the permit. The state's online lookup wouldn't load for this manual, so there's no link here. DORA can tell you how to verify a license.

Before you hire

Plumber's state license numberIN WRITING
Contractor registrationIN WRITING
Electrician's license numberIN WRITING
Pump contractor's licenseIN WRITING
Who pulls the permitNAMED IN THE BID
Inspection before covering workAGREED
Scope and materialsIN WRITING
Permit cardSEEN ON SITE

Compare more than one written bid where you can. A clear layout of services helps you see what a bid covers. This Pennsylvania company's page is one example of the format.

Linked from this manual

Plumbing services page. A Pennsylvania service company in Bucks and Montgomery counties, not in Colorado. Only an example of how a plumbing outfit lays out its services. This manual’s team is connected with Central Plumbing & HVAC.

Also asked

Can I replace a water heater in a house I am about to sell?

DORA's addendum excludes a home that is for sale, resale, a flip or a rental. Use a licensed plumber working for a registered contractor. Ask your permit office if your plans are unsettled.

Does the owner exemption cover my rental unit or a tenant's repair?

No. The published statute says the plumbing exemption doesn't cover rentals. Hire a licensed plumber, and see §10-1 for permits.

Can my brother-in-law do it as a favor?

The sources behind this manual don't address a helper working on your house. Ask the permit office before relying on the exemption. If he's licensed, the question goes away.

Do I need a license to change a well pump on my own land?

The statutes as published say a private pump installer using its own equipment for its own use on its own land is exempt from license requirements, but still under construction standards and board rules. Another section says only a licensed contractor may install a cistern between wellhead and pressure tank. See §2-2, and ask the Division of Water Resources or a licensed installer.

Where this comes from

Colorado statute 12-155-118, plumbing exemptions: own property exemption and its limits (published copy of the statute).
Colorado statute 12-155-120, plumbing permits: permits and homeowners (published copy of the statute).
Colorado statute 12-155-108, plumbing licenses: license types, contractors, apprentices (published copy of the statute).
Colorado statute 12-115-116, electrical exemption: owner work (published copy of the statute).
Colorado statute 12-115-110, electrical licenses: license types (published copy of the statute).
Colorado statute 37-91-102, pump definitions: pump contractor, private installer (published copy of the statute).
Colorado statute 37-91-106, exemptions: private pump installers (published copy of the statute).
Colorado statute 37-91-109, wells and cisterns: licensed contractor for cistern placement (published copy of the statute).
DORA addendum, December 4, 2025: homeowner water heaters.
DORA memo, December 3, 2025: licensed plumber wording, superseded for homeowners.
Mesa County, permit application, April 2023: license numbers on the form.
Mesa County, sample inspection card, May 2023: notice on licensed work.

Sources checked November 4, 2026.