Hot water pipe length in Surprise, AZ: the City struck the 100 foot limit for homes

Surprise's amendment document shows each change as struck or underlined text. On the residential code's page, the whole of P2905.3 is struck, heading and all, and nothing is written in its place.

The model text Surprise removed reads: "The developed length of hot water piping, from the source of the hot water to the fixtures that require hot water, shall not exceed 100 feet (30 480 mm). Water heaters and recirculating system piping shall be considered to be sources of hot water."

With the section struck, the residential code in Surprise sets no maximum length for that pipe (a reading; the plan reviewer has the final word on a set of plans).

A second line in the same document matters here. Surprise's list of work exempt from permit under R105.2 names "Hot water re-circulators" as Plumbing item 3. Adding a recirculating pump to an existing home needs no permit in Surprise.

• Developed length: the full run of pipe as installed, counting every turn and rise, not the straight line on a floor plan.
• Source of hot water: the water heater, or under the struck model text, a recirculating loop that keeps hot water moving near the fixtures.
• Recirculating pump: a small pump that returns cooled water from the far end of the hot line to the heater, on a timer, a button or a sensor, so hot water is waiting close to the tap.
• Point-of-use heater: a small heater under a sink or near a bathroom that serves only the fixtures beside it.

One- and two-family homes and townhouses in Surprise built or altered under the residential code: new homes, additions, remodels that move a bathroom or kitchen, and water heater moves. Commercial buildings and apartments are under the plumbing code instead, and a restaurant or other permitted food business in Surprise also answers to Maricopa County Environmental Services, which keeps a 60 foot limit and a 45 second test.

• A single-story home with the heater in the garage. The primary bath is at the far corner of the house. In Phoenix, a run past 100 feet would need a recirculating loop or a second heater to pass. In Surprise it passes as drawn. Whoever showers there still runs the tap until the cold water in the pipe clears.
• A casita added behind a Surprise home. The owner wants to tee off the main house's hot line. The code no longer stops a long run. A small point-of-use heater in the casita can still beat a long trench of hot pipe on wait time and wasted water.
• A sandwich shop moving into a Surprise strip center. The county's plan review asks for hot water at every sink within 45 seconds and no more than 60 feet of pipe from the source. The City's change to the home code does not help here.

1. 1Measure the hot water run on your plans from the heater to the farthest fixture, counting every turn.
2. 2If it is long, decide how you will shorten the wait: move the heater closer, add a recirculating pump, or put a point-of-use heater near the far fixtures.
3. 3Show the heater location and any loop on the plumbing plan, and ask the City's plan reviewer to confirm nothing else applies to your project.
4. 4For a recirculating pump on an existing home, Surprise asks for no permit.
5. 5For a food business, plan to the county's 60 feet and 45 seconds before the plans go in.

• "No limit means it doesn't matter." The code limit is gone, not the physics. A long pipe holds more cold water, and every gallon runs down the drain before the hot water shows up. Our page on why hot water takes so long to reach a shower walks through the math.
• "Surprise dropped the rule for restaurants too." The county's food rule is separate and still applies.
• "A recirculating pump needs a permit." Not in Surprise. The City's R105.2 list exempts hot water re-circulators.

The best time to plan a hot water run is before the walls close or the slab is poured. A plumber can place the heater where the runs are shortest, size the pipe so it holds less cold water, and add a return line for a recirculating pump if the far bathroom needs one. In an existing home, a pump that uses the cold line as its return, or a small heater at the far end, can cut the wait without opening walls. Read whether a recirculation pump is worth it and what a point-of-use water heater is for the trade-offs. HQ Plumbing & Air installs and replaces water heaters in Surprise. See our water heater and Surprise plumbing pages, or contact us to talk through a long wait for hot water.