The most common plumbing problems are dripping faucets, running toilets, hidden leaks, clogged drains, sewer backups, water heater trouble, low or high water pressure, and hard-water scale. Most are preventable: keep cooking fat and wipes out of drains, test for leaks twice a year, flush the water heater yearly, and keep pressure between 45 and 60 psi.
The common problems at a glance
Here's the whole picture in one table. The last column is the honest answer on whether most homeowners can handle it.
| Problem | Usual cause | How to prevent it | DIY or call? |
|---|---|---|---|
| Dripping faucet | Worn washer, O-ring or cartridge | Fix drips when they start; clean scale off aerators | Usually DIY |
| Running toilet | Worn or scaled flapper, misadjusted fill valve | Dye test twice a year; new flapper every five years | Usually DIY |
| Hidden leak or slab leak | Failed fittings, pinholes, pipes under the slab | Meter test twice a year; watch the water bill | Call for leak location |
| Kitchen sink clog | Grease, food scraps, coffee grounds | Grease in the trash, scraps in the bin, cool water with the disposal | DIY first, call if it returns |
| Bathroom drain or toilet clog | Hair, soap scum, wipes | Hair catchers; flush only toilet paper | DIY first |
| Sewer backup | Grease and tree roots in the main line | Keep grease and wipes out; camera older lines | Call |
| Water heater problems | Sediment and scale, worn anode, failing relief valve | Flush yearly; test the relief valve; service it on schedule | Flushing is DIY; gas and repairs, call |
| Low or high water pressure | Failing pressure regulator, scale, partly closed valve | Check pressure with a gauge once a year | Gauge is DIY; regulator is a plumber job |
| Hard-water scale | Calcium and magnesium in the water | Clean aerators and showerheads; consider a softener | DIY cleaning; softener install, call |
Across all of these, one habit does the most good: look and listen. Most plumbing failures announce themselves before they do real damage.
Leaks, drips and running toilets
Leaks come first, and the EPA puts real numbers on them. "Household leaks can waste nearly 1 trillion gallons of water annually nationwide," EPA WaterSense says. At the household level, "the average household's leaks can account for more than 9,300 gallons of water wasted every year and nine percent of homes have leaks that waste 50 gallons or more per day." The same page lists worn toilet flappers, dripping faucets and other leaking valves as the common types, and says these are often easy to fix.
### Dripping faucets and showerheads
A drip looks harmless. It isn't. EPA WaterSense says "a leaky faucet that drips at the rate of one drip per second can waste more than 3,000 gallons per year." Showerheads add up too: "a showerhead leaking at 10 drips per minute wastes more than 500 gallons per year."
The cause is almost always a worn washer, O-ring or cartridge. In the Valley, mineral scale speeds that wear along. Prevention is simple: fix the drip the week it starts, and clean scale off aerators and showerheads when you notice flow dropping. Our guide on how to fix a dripping faucet walks through the repair by faucet type.
### Running toilets
A toilet that runs, refills on its own or hisses between flushes is usually leaking past the flapper. EPA WaterSense says the flapper "should be checked periodically and replaced at least every five years to ensure a good seal and avoid leaks." A worn one can also make the toilet flush on its own.
To check yours, put a few drops of food coloring in the tank and wait. EPA says that if color shows up in the bowl after 10 minutes, you have a leak. Flush right after so the dye doesn't stain. See how to fix a running toilet for the flapper, fill valve and chain fixes.
### Hidden leaks and slab leaks
Some leaks never show. Supply lines run inside walls, under cabinets and, in most Arizona houses, under the concrete slab. The EPA's meter test catches them: read your water meter, use no water for two hours, and read it again. EPA says that if the meter changes at all, you probably have a leak.
A warm spot on the floor, the sound of running water with everything off, or a bill that jumps for no reason are the classic slab-leak signs. Our pages on the signs of a slab leak and why slab leaks are common in Arizona explain what to look for and why the desert makes them more likely. For a room-by-room hunt, use how to detect leaks in your home.
Do the meter test twice a year. That's the play.
Clogs and sewer backups
Clogs are the second big family of problems, and nearly all of them come from what goes down the drain.
### Kitchen sinks and disposals
Grease is the number one enemy. The City of Phoenix says "grease is the most frequent cause of sewer problems," and that grease poured down a drain, even when followed by hot water, cools, congeals, builds up and hardens into a plug. The fix is free: let grease cool in the pan, scrape it into the trash, and wipe the pan before washing.
Coffee grounds, eggshells and fibrous scraps pile up in the trap too. Run cool water while the disposal grinds, and feed it gradually. Our pages on how to unclog a kitchen sink and what not to put down the drain cover the rest.
### Bathroom drains and toilets
Hair and soap scum are the bathroom version of grease. A simple hair catcher in the shower and a pull-and-rinse of the sink stopper every month or so prevents most bathroom clogs. For toilets, the rule is short: flush only toilet paper. Wipes labeled "flushable" are the usual exception people get wrong, and our page on whether flushable wipes are safe to flush lays out why. If one drain keeps clogging, why the same drain keeps clogging helps you find out whether the problem is local or deeper.
### Sewer backups
When several drains back up at once, or the tub fills when you flush, the main sewer line is the likely spot. The City of Phoenix says "the two primary causes of sewer backups and overflows are grease and roots." Keep grease and wipes out, plant trees well away from the sewer line, and treat a slow main drain as an early warning. Our guides to maintaining your sewer line and preventing sewer backups before monsoon give the full routine.
A main-line clog is not a DIY job. Once more than one fixture is involved, call a plumber.
Water heaters, water pressure and hard water
These three problems are linked in the Phoenix area. Hard water creates scale, scale settles in the water heater, and pressure that runs too high wears on the whole system faster.
### Water heater problems
Sediment is behind many of the classic water heater complaints: popping or rumbling noises, less hot water than before, and eventually a leak. EPA WaterSense recommends that you flush your water heater once a year to reduce sediment buildup, and check the temperature and pressure relief valve at least once a year. It adds that it may be best to have a professional service the water heater at least once a year. A. O. Smith, a water heater manufacturer, goes further for hard-water areas: "Have your hot water heater serviced once a year. If you have hard water in your area, get it serviced twice a year since mineral buildup happens faster."
Our page on how often to flush a water heater in Phoenix covers timing and steps. If yours is already leaking at the base, read water heater leaking from the bottom first.
### Low or high water pressure
Pressure problems go both ways. EPA WaterSense says your water-using fixtures will operate best if incoming pressure is between 45 and 60 psi, and that your home may have a pressure-regulating valve (PRV) to hold it in that range. Too low, and showers feel weak. Too high, and it's hard on pipes, valves and appliances.
A screw-on gauge at a hose bib tells you where you stand in about a minute. Check it once a year. If pressure is low everywhere, start with low water pressure in the whole house; if only one fixture is weak, see low water pressure at one fixture. Our page on what home water pressure should be explains the code limits.
### Hard-water scale
The USGS says hard water is high in dissolved minerals, largely calcium and magnesium, and that it "can cause mineral buildup in plumbing, fixtures, and water heaters, and poor performance of soaps and detergents." It classifies water above 180 mg/L as calcium carbonate as very hard. Phoenix water sits in the hard to very hard range, and our page on how hard Phoenix water is gives the local numbers.
You can't stop the minerals at the tap, but you can manage them. Soak aerators and showerheads in vinegar when flow drops, flush the water heater on schedule, and consider a water softener if scale keeps winning. How hard water damages plumbing shows where scale does the most harm.
A simple prevention routine
You don't need a plumber's toolkit to prevent most of this. Here's a routine that covers every problem in the table.
Every month
- Pull and rinse bathroom sink stoppers and shower hair catchers.
- Look under kitchen and bathroom sinks for drips or water stains.
- Listen for toilets that refill on their own.
Twice a year
- Do the EPA meter test: two hours, no water use, meter unchanged.
- Do a dye test on every toilet.
- Clean aerators and showerheads.
Once a year
- Flush the water heater and test its relief valve.
- Check your water pressure with a gauge.
- Know where your main shutoff is, and make sure it turns.
For a full calendar with seasonal tasks, use our yearly plumbing maintenance checklist. EPA WaterSense also says that fixing easily corrected household leaks can save homeowners about 10 percent on their water bills, so the routine pays you back.
Some jobs are worth handing off: anything on a gas water heater, a sewer line, a slab leak, or a pressure regulator. HQ Plumbing and Air is licensed and insured, offers 24/7 emergency service, and gives free estimates with upfront pricing before any work starts.