Do you need a permit to switch to a tankless water heater in Chandler?

Chandler City Code 29-6.7 adds a gas item to the International Residential Code's list of work exempt from permit: "Replacement of gas water heating equipment where the replacement equipment is of equal or lesser BTU capacity and is placed in the same location as the existing equipment." That is Gas item 4.

For electric units, Plumbing item 5 reads: "Replacement of electric water heating equipment where the replacement equipment is of equal or lesser amperage rating and is placed in the same location as the existing equipment."

Both Chandler lists end with a catch-all: "Special cases as allowed by the Building Official for work of a similar nature and complexity as those items listed above."

The Homeowner Building Permit Manual (Rev. 4/09/26) says the short version. Item 10 on its Work Exempt from Permit list is "Like for like replacement of residential water heaters and water softeners," among other equipment. The manual does not define "like for like."

Chandler adopted the 2024 International Residential Code with these amendments under Ordinance 5108, effective July 1, 2025. The straight tank-for-tank swap is covered on our Chandler water heater replacement permit page. This page picks up where that one leaves off.

• Water heating equipment: the code's term. It does not split tank and tankless units. Our reading is that a tankless gas heater is still gas water heating equipment, so the same two conditions apply to it.
• BTU capacity: the heater's gas input rating. The code uses the term but does not define it.
• Same location: not defined in the code. Our reading is the same spot the old heater occupied.
• Like for like: the manual's phrase, also undefined. Whether a tankless unit is "like for like" with a tank is a question the manual does not answer.

It covers a Chandler homeowner or licensed contractor replacing a residential water heater with a tankless one. The manual says "Any construction requiring a permit also requires that a licensed contractor do the work unless the owner-applicant performs the work." It adds: "If you own a home that you lease or rent to others, a licensed contractor is required to obtain a permit."

This does not apply if the building falls under the International Building Code instead. That code's list is City Code 29-2.11, and its gas water heater item is limited to equipment affixed to a Group R-3 occupancy, under the same BTU and location conditions.

The exemption also does not stretch to the piping around the heater. The manual's exempt list says ordinary repairs "shall not include addition to, alteration of, replacement or relocation of any standpipe," and the list that follows names gas and vent piping. It also warns that exemption "shall not be deemed to grant authorization for any work to be done in any manner in violation of the code." Exempt work still has to meet code.

When a job needs a new gas line, the manual's Gas Permits page starts: "When adding a gas line inside the residence, or attaching to an existing gas stub out, you will need to:" and then asks for a riser schematic from the meter. One item on that list: "Provide the total BTU rating of each appliance." The full list is on our Chandler gas line permit page.

The clean match. A homeowner replaces a gas tank in the garage with a gas tankless unit whose BTU rating is no higher than the old tank's, mounted where the tank stood, on the existing gas line and vent. On our reading, both conditions of Gas item 4 are met. The city never names tankless units, so this remains our reading.

The bigger burner. The tankless model the family picks has a higher BTU rating than the tank it replaces. Chandler's Gas item 4 only covers "equal or lesser BTU capacity," so this swap falls outside the exemption, whatever the tank sizes were.

The move outside. The owner wants the new unit on an exterior wall to free up garage space. Chandler's code requires the replacement to be "placed in the same location as the existing equipment," so a relocation is not exempt.

The edge case: the gas line. The swap starts out matching on BTU and location, but the installer finds the existing line has to be replaced with a larger one. The heater swap alone might have fit the exemption. The gas piping work does not, because the manual's ordinary repairs exclude replacing gas piping. The answer flips on the pipe, not the heater.

1. 1Find the BTU rating (gas) or amperage rating (electric) of the old heater and the new one, and decide whether the new unit goes in the same spot.
2. 2List any gas line or vent changes the installer expects. Any "yes" there takes the job past an ordinary repair.
3. 3Before starting, put the specifics to the Plan Reviewer of the Day. The manual says: "For questions regarding if a permit is required or not contact the Plan Reviewer of the Day at 480-782-3078 or e-mail them at prod@chandleraz.gov."
4. 4If a permit is needed, decide who files. An owner-applicant can pull it for their own home; a rental home needs a licensed contractor to obtain it.
5. 5Apply through the city's CLICS portal (developmentpermits.chandleraz.gov/clics) or at the Development Services counter, 215 E. Buffalo St. (480-782-3000).
6. 6Book inspections at least one business day ahead, by phone at 480-782-3100 or by text to 844-281-3520. Chandler's inspection list includes 742 Water Heater Changeout, and gas piping work has its own codes, including 735 Rough Gas Piping Test and 746 Gas Final.

HQ's licensed and insured plumbers install tankless water heaters in Chandler and can handle the permit when the job needs one.

• Tankless is a different product, so it always needs a permit. Chandler's code does not say that. Gas item 4 turns on BTU capacity and location, not tank type. Mesa is different: its FAQ lists a storage-to-tankless gas swap as permit required, which you can read about in our Mesa tank to tankless FAQ.
• Same gallons means same BTU. Tankless units have no tank at all, and the exemption is by BTU capacity. Compare the ratings, not the sizes.
• The heater swap was exempt, so the gas line is too. The manual's ordinary repairs exclude gas and vent piping work. Who can do that work is covered in our gas line permit FAQ.
• No permit means no rules. The manual says exemption does not authorize work "in any manner in violation of the code."

This page explains Chandler's published exemption rules as checked on the date above; the city names no tankless rule, so the Development Services counter decides any specific conversion.