UPC Section 507 sets the general installation rules for a water heater: it must be accessible for service, anchored against movement, and placed where a code official allows it. These rules sit alongside the separate requirements for relief-valve discharge, clearances, and drain pans that also govern a safe install.
The Uniform Plumbing Code is published and copyrighted by IAPMO. This page explains the section in our own words with a short excerpt only. Read the full official text at the source.
A water heater is a pressurized tank of hot water with a heat source, so the code treats its installation as a safety job, not just a hookup. UPC Chapter 5, which includes Section 507, sets the general rules for how a water heater goes in. The goal is a heater that can be serviced, that stays put, and that sits in a location the code allows.
What this section requires
Section 507 and the rest of Chapter 5 cover the installation basics that apply to nearly every water heater. Three ideas carry most of the weight.
First, access. A water heater has to be installed so it can be inspected, serviced, and replaced. A unit crammed into a space where no one can reach the controls or swap the tank fails this rule.
Second, anchoring. The code requires a water heater to be secured against movement. In seismic regions this means strapping the tank so an earthquake cannot tip it and shear the water or gas lines:
Water heaters shall be anchored or strapped to resist horizontal displacement due to earthquake motion.
The strapping is placed in the upper and lower thirds of the tank's height. Phoenix sits in a low-seismic area, so local practice on strapping can differ from high-seismic states; confirm the current Phoenix amendment.
Third, safe placement. The code limits where a heater with a burner can go and how it gets combustion air, and it works together with the separate rules for the temperature-and-pressure relief valve and its discharge pipe, required clearances, and a drain pan. Those live in their own sections but are part of the same safe install.
When this comes into play
This section governs every water heater swap and new install. Picture a homeowner replacing a failed heater in a hall closet: the new unit has to keep enough access to service it, be anchored per the local amendment, and keep its relief-valve discharge and any pan routed correctly. An inspector checks these before signing off a permitted replacement.
What this means for you
If you are replacing a water heater, the code details decide whether the job passes inspection, so they are worth knowing before you buy. Start with the applied guides: water heater clearance and access rules, the garage 18-inch rule, and seismic strapping in Arizona. Because a water heater is both a plumbing and a safety appliance, a permitted install by a licensed plumber is the way to be sure every one of these sections is met. See our water heater service for a code-compliant swap.
Full text and source
UPC Section 507 is part of the Uniform Plumbing Code. IAPMO publishes and holds the copyright on it. The excerpt above reflects the rule as adopted; Phoenix enforces the 2024 UPC with local amendments, and exact section numbers can shift between editions, so verify the current text. Read Chapter 5 on UpCodes or the official 2024 UPC, and confirm local amendments through the City of Phoenix: phoenix.gov/pdd.
Keep Reading
- UPC 506: Combustion Air for Gas Water Heaters
- UPC 510: Venting Gas Water Heaters (Category I Flues)
- UPC Section 608: Water Heater Relief Valve and Discharge Pipe Rules
- UPC Water Heater Drain Pan: When One Is Required and How It Drains
- How much clearance and access does a water heater need?
- Does a water heater have to be 18 inches off the garage floor?
- Do I need to strap my water heater in Arizona?