How to check a plumber's license for a Chicago water heater job

Who licenses plumbers in Illinois?

The Illinois Department of Public Health (IDPH) runs the state plumbing program. It licenses plumbers, plumbing contractors, apprentice plumbers, irrigation contractors and retired plumbers, about 8,900 plumbers and 2,000 apprentices in all^[1]. Plumber license applicants must first spend at least 4 years as a licensed apprentice^[1], so a licensed plumber has real supervised time behind the card.

Two other layers sit on top of that in Chicago:

Layer	Who it covers	What to ask for
IDPH plumber license	The individual plumber	The license number, checked on IDPH's verification tool[1]
IDPH contractor registration	The plumbing business; all contractors must register and pay an annual fee[1]	The business's registration
City of Chicago	Plumbing work in the city is done by a Chicago-licensed and bonded plumbing contractor[2]	Proof the company holds a current Chicago plumbing contractor license

The Illinois Plumbing License Law also requires plumbing to be done by licensed plumbers or supervised licensed apprentices^[3]. The narrow exception for an owner-occupant of a single-family home is covered in Chicago water heater permit rules.

How do you check the license, step by step?

1. Get the number. IDPH says every advertisement for plumbing services must include the plumbing license number^[1]. Look on the ad, truck, website or estimate. If it is missing, ask.
2. Look it up. Enter the number or name in IDPH's plumbing license verification tool, linked from the IDPH plumbing program page^[1]. Confirm the name matches the person who will do or supervise the work, and that the license is current. Plumber licenses must be renewed by April 30 following the date of issuance^[1].
3. Check the business. Ask for the company's IDPH contractor registration and, for a job inside city limits, its Chicago plumbing contractor license^[1][2].
4. Match the paperwork. The name on the license, the business name on the contract and the name on the invoice should line up.

IDPH warns that displaying the wrong license number or sharing license numbers can be prosecuted as a Class A misdemeanor and may lead to a $1,000 fine and suspension or revocation of the license^[1]. A borrowed number is not a small paperwork issue.

What should the contract say?

If your quote is over $1,000, Illinois' home repair rules give you specific rights. The Illinois Attorney General's consumer guide says^[4]:

• For home repair contracts over $1,000, you have the right to a written contract or work order that describes the work and states the total cost, with parts and materials described in some detail, such as quality and grade.
• The contractor must give you the brochure "Home Repair: Know Your Consumer Rights." For contracts over $1,000, you sign an acknowledgment and get a copy.
• The contract should set the timing and the payment schedule, including any down payment.
• If the contractor fails to begin or complete work within the contracted time, you may cancel and may be entitled to a refund of payments on written demand by certified mail.
• If the sale is made at your home and is over $25, you have three business days to cancel.

Before you pay, the Attorney General also suggests asking for a signed statement listing anyone the contractor hired or bought materials from, and getting lien waivers, because unpaid suppliers can file a lien against your home under the Mechanics Lien Act^[4].

Red flags specific to water heater jobs

• No license number on the ad or estimate, or a number that does not match the name on IDPH's tool^[1].
• A quote for tankless or a bigger unit with no mention of whether the city needs a permit. See Chicago water heater permit rules.
• A crew of unlicensed helpers on an owner "self-install." The owner-occupant exception bars employing anyone but a licensed plumber^[3].
• Pressure to sign the same day with a large down payment and no written schedule^[4].

If you think a contractor has defrauded you, the Attorney General's office points you to your state's attorney or the Attorney General's consumer fraud hotline^[4].

When to call a pro

• Any water heater replacement in a home you rent out or do not live in: hire a licensed and registered plumbing contractor.
• Gas, venting, relief valve or electrical changes: a licensed plumber, and a licensed electrician for new circuits.
• You found an unlicensed job after the fact: have a licensed plumber inspect the installation before you rely on it.