Safe to DIY: clearing a simple clog, replacing a faucet, showerhead, flapper or fill valve, and fixing a drip at an accessible valve. Stop and get a permit or a plumber for gas piping, concealed pipe replacement, moving fixtures, and any job where a mistake floods the house.
Which repairs are reasonable to do yourself?
These have low stakes and an easy shutoff. If you can close a valve and the worst outcome is a wet cabinet, you're in the safe zone.
### Clogs, faucets and toilet parts
- Clearing a simple clog with a plunger or a hand auger. See how to fix a slow-draining sink.
- Replacing a faucet, showerhead or aerator. Take a look at how to replace a kitchen faucet if that's the job.
- Swapping a toilet flapper or fill valve. EPA's WaterSense program calls flapper replacement quick and easy, and says to replace flappers at least every five years. Our guide to replacing a flapper and fill valve walks through it.
- Unclogging a toilet. Most are a plunger job. See why your toilet keeps clogging if it keeps happening.
- Replacing washing machine hoses. It takes a pair of pliers and a few minutes with the water off. Our page on how often to replace washing machine hoses says when to do it.
- Fixing a dripping faucet or a leaking stop valve that you can isolate. See how to fix a dripping faucet.
### Finding a leak
Diagnosis is always safe. EPA suggests reading your water meter before and after two hours of no water use, and dropping food coloring in the toilet tank to check for a silent leak. Our page on the water meter leak test shows the steps.
### Why Phoenix's permit rules agree
Phoenix's permit exemptions line up with this list. Section 105.2 exempts clearing stoppages, repairing leaks in pipes, valves or fixtures, and replacing valves or fixtures with new ones that meet the code's water conservation requirements, as long as you aren't relocating anything. In other words, the city treats like-for-like fixes as low risk, and so should you.
Which repairs need a permit or a plumber?
The common thread is a job that can't be undone by closing one valve, or a mistake you can't see.
- Gas piping and gas appliances. A gas mistake isn't a puddle. Read who can install a gas line in Arizona before you consider it.
- Replacing a water heater. Phoenix exempts an in-kind swap from a permit only when a licensed contractor performs the work, so a homeowner swap needs a permit. See permit to replace a water heater in Phoenix.
- Replacing concealed pipe. Under Section 105.2, if a concealed drain, water, waste or vent pipe is defective and has to be removed and replaced with new material, that counts as new work and a permit is required. A repipe is a permitted job.
- Moving a fixture, valve or pipe. The exemption for replacing fixtures specifically excludes relocation.
- Sewer line work, backwater valves and anything under the slab, where a mistake is buried and expensive to reach.
- Backflow assemblies. Phoenix's exemption for repairing small secondary assemblies comes with a test report from a certified backflow tester.
### The gray zone
Some jobs sit in between: replacing a shower valve, adding a shutoff behind a wall, or swapping a hose bib and its vacuum breaker (see the hose bib vacuum breaker). They can be done at home, but they involve opening a wall or cutting into supply lines. If any part of the job means cutting into a concealed pipe, stop and check the permit rule first. Ask yourself, too, whether you can reach the valve that shuts the water off to that section. A job you can't isolate is a job that can flood the house while you're halfway through it, and that's the moment to hand it over rather than hurry. Our page on what plumbing work needs a permit in Phoenix lists the exemptions in full.
What does Arizona say about doing your own work?
A.R.S. 32-1121 exempts owners who do the work themselves on property intended for their own occupancy, not for sale or rent. The statute treats a sale or rental within one year after completion as prima facie evidence the project was for sale or rent. If you're flipping a house, this exemption isn't for you. Can I do my own plumbing in Arizona has the details.
The exemption covers the license. It doesn't cover the code, and a leak you cause is still your leak. Your work still has to meet plumbing code and pass inspection where a permit applies, and a future buyer's inspector will look at it.
What about chemical drain cleaner?
It looks like a DIY shortcut, but it isn't always safe. Poison Control says many drain cleaners contain highly concentrated corrosive chemicals and must be used with great caution, and that splash-back can happen if the cleaner is poured from too high or if too much goes into a completely blocked drain. It recommends goggles and rubber gloves.
If a plunger and an auger won't move the clog, that's a sign to call rather than pour. A clog that returns in more than one drain can mean a main line problem, which no bottle fixes. Our page on enzyme cleaners covers the gentler option, and main line versus branch clogs shows how to tell what you're dealing with.
### Safety habits that apply to every repair
Before any DIY job, shut off the water to what you're working on, and open a faucet to relieve pressure. Have a bucket and towels ready. If the job is anywhere near a water heater, switch off its power or set the gas control to pilot first, and let the tank cool, because the water inside can scald. Our page on the right water heater temperature explains why the setting matters. If you smell gas at any point, leave the house and call the gas utility from outside. Our page on turning off gas to the house covers the shutoff for emergencies.
### What if a DIY repair goes wrong?
Close the fixture stop, or the main shutoff if you can't stop the flow. Move anything valuable out of the water's path, and take photos before you clean up, since you'll want them for any insurance claim. Then call a plumber instead of trying a third fix. Repeated attempts on a damaged fitting or a split pipe usually make it worse. Our page on filing a water damage insurance claim explains what to document.
How do you decide before you start?
Ask yourself three things. Can I shut the water off to just this fixture? Is any part of the job gas, sewer or hidden inside a wall? Would I know what to do if the joint let go? If the answers are yes, no and yes, go ahead. Any other combination, get an estimate first.
Two more habits help. Read the most common DIY plumbing mistakes before you start, and keep the basic tools every homeowner should own within reach. If you end up in over your head, HQ Plumbing & Air is licensed and insured, offers 24/7 emergency service, gives free estimates, and quotes the price upfront before work starts.