What Usually Goes Wrong With a Gas Tank
Most gas water heater problems trace back to the pilot or ignition, the thermocouple, the gas control valve, a clogged flame arrestor, or venting that isn't drawing right. Each can usually be repaired without replacing the tank. We check the gas supply and venting first for safety, test the parts, and explain the price before we start.
A burner under the tank heats the water, and exhaust rises through a center flue and out the vent. A pilot or igniter, a flame sensor and a control valve keep that safe. When one fails, the burner shuts down.
Safety: If you smell gas (a rotten-egg odor) near the heater, don't try to light anything, don't flip switches and don't use your phone inside. Get everyone outside first. From there, phone 911 and then Southwest Gas, or whoever supplies your propane.
For electric and tankless heaters and other repairs, see our main water heater repair service.
Gas Water Heater Repair Apache Junction, AZ: Parts We Test
- Pilot and ignition: pilot tube, piezo igniter, or the electronic igniter on newer models.
- Flame sensor: the thermocouple, or the thermopile on some models.
- Gas control valve: the knob-and-dial unit on the front of the tank.
- Flame arrestor and air intake: the screen at the base of most newer tanks.
- Venting and draft: the draft hood, vent connector and flue.
- Burner and flue: rust flakes, soot and a dirty burner.
To rule out simple causes first, like a closed gas valve, use our no hot water checklist.
Pilot and Ignition Problems
Standing pilot or electronic ignition: which do I have?
Most gas tanks here use a standing pilot, a small flame that burns all the time and lights the main burner when the water cools. You'll see a knob with Off, Pilot and On, plus a push-button igniter. Some newer tanks have electronic or hot-surface ignition instead: there's no pilot to light, the unit plugs into an outlet, and a status light blinks codes when something is wrong. Those need power to run, so an outage leaves them cold.
Why does the pilot keep going out?
Usually a worn thermocouple, a dirty pilot tube, a clogged flame arrestor or a draft. We test each part rather than guess. If you want to try relighting it yourself first, our guide on how to relight a water heater pilot covers the steps and when to stop. If it won't stay lit after one careful try, that's our job.
Thermocouple, Thermopile and Gas Control Valve
What does the thermocouple do?
The thermocouple is a thin copper rod with its tip in the pilot flame. Heat makes it produce a tiny electric signal that tells the gas valve the pilot is lit. When the tip wears out or gets crusted, the signal fades and the valve shuts the gas off. Some tanks use a thermopile, a stronger version that also powers the valve's controls. We test the signal with a meter before swapping either.
When does the gas control valve need replacing?
Far less often than people expect. Signs include a pilot that won't hold with a good thermocouple, or a burner that won't fire while the pilot is fine. On an older tank, a new valve often prompts a repair-or-replace talk.
Water dripping near the valve is a different problem. It is usually a fitting, the threads where the valve meets the tank, or something dripping from above. Our page on a water heater gas valve leaking water sorts those out, and if a leak has put the pilot out, read leaking with no hot water.
Flame Arrestors and Dusty Garages
Most gas tanks built in roughly the last two decades use a flammable vapor ignition resistant (FVIR) design. The burner sits in a sealed chamber, and air comes in through a flame arrestor screen at the base. It keeps the flame from reaching fumes from stored gasoline or solvents.
It also catches dust, lint, leaves and pet hair. In Apache Junction garages and outside closets, where desert dust blows in every time a door opens or a monsoon storm passes, the screen can clog until the burner starves for air. The flame turns lazy and yellow, or the heater locks out.
Can I clean the flame arrestor myself?
You can gently vacuum dust from the outside of the intake area with the heater off. Cleaning the arrestor itself, or opening the sealed chamber, is a job for us, because a damaged seal defeats the safety design. Our post on garage water heaters in Arizona heat covers keeping the area around a garage tank clear.
Venting, Draft and Carbon Monoxide
A gas heater makes carbon monoxide as it burns. The vent pipe must carry all of it outside. When a vent is blocked, loose or rusted through, exhaust can spill back into the room. That's backdrafting.
What are the signs of backdrafting?
- Soot or scorch marks around the draft hood on top of the tank
- Melted or discolored plastic on fittings near the top
- A flame that rolls out of the burner area, or a pilot that flickers when doors close
- A carbon monoxide alarm going off, or headaches and nausea that ease when you leave the house
Safety: If a CO alarm sounds or anyone feels sick, get everyone outside and call 911. Every home with a gas appliance should have working CO alarms.
Some dripping on a cold start is normal condensation, not a vent problem; our condensation vs. leak guide explains how to tell. We check the draft with the burner running, the vent joints, and the combustion air supply.
Burner and Flue Cleaning
Rust flakes from the flue drop onto the burner over time, and soot builds up if combustion isn't clean. A healthy flame is mostly blue; a yellow, noisy one wastes gas. On older open-burner tanks we clean the burner and pilot area and brush the flue. On sealed FVIR tanks we work through the maker's service openings. Heavy rust falling from the flue also hints at the tank's age.
Southwest Gas, Propane and Mobile Homes
Most gas heaters in Apache Junction run on Southwest Gas, and some homes nearby are on City of Mesa gas. Outlying homes often run on propane. Propane and natural gas heaters are built differently. If your stove has no flame either, call your gas company or propane supplier first.
In manufactured homes, a gas water heater has to be a model listed for manufactured-home use, often sealed-combustion and set in a closet that opens from outside. A store-shelf tank isn't a legal swap. Our mobile home water heater repair page explains what's different.
Should You Repair or Replace a Gas Water Heater?
Pilots, thermocouples, igniters and arrestor cleaning are inexpensive next to a new heater, so a repair usually makes sense on a dry tank under about 8 years old. A new gas control valve on a 10-year-old tank, rust falling from the flue, or water from the tank body tilts the answer toward replacement. Our repair or replace guide goes through the decision.
Under Apache Junction's code, a like-for-like gas swap (same or smaller Btu input, only minor connection changes) needs no fuel gas permit, provided the venting and combustion air meet current code. Bigger units and venting changes aren't covered. Our permit guide has the details; confirm with the city or county for your address.
What Gas Water Heater Repairs Cost
For a local benchmark, Angi's average for all kinds of water heater repair in Apache Junction is about $646, typically $422 to $1,196. That figure blends every repair together, so it isn't the price of a thermocouple or a valve. When replacement wins, Angi's Apache Junction install average is about $1,136, and Phoenix-area tank replacements average about $1,224. See our replacement cost page for what moves that number. We test first and quote before any work.
Gas Water Heater Repair in Apache Junction, AZ, Day or Night
We're open 24/7 at +1 480-863-0807. Tell us the heater's age and what you've tried. If water is also on the floor, see water heater leak repair in Apache Junction for how to stop it, and our emergency service handles urgent calls. From garage tanks in 85119 to outside-closet units in the parks, gas water heater repair in Apache Junction, AZ starts with safety checks, then the fix.
Gas Water Heater Repair Apache Junction, AZ: FAQs
How long does a thermocouple last on a gas water heater?
Many last for years, but there's no set lifespan. Heat, a dirty pilot flame and dust in the burner area wear them out faster. A thermocouple that fails on a younger tank is common and cheap to replace. When one fails repeatedly in a short time, the pilot flame, the burner air supply or the gas valve usually needs a closer look.
Why does my gas water heater make a whooshing sound when it starts?
A soft whoosh as the main burner lights is normal. A loud bang, a delayed ignition or a flame that rolls out of the burner area is not. Those can mean a dirty burner, a clogged air intake or a draft problem. Turn the gas control to Off and call us rather than letting it keep lighting that way.
Can I store things next to my gas water heater?
Keep the space around it clear. Boxes, laundry and lint crowd the air the burner needs, and anything that gives off fumes, such as gasoline, paint thinner or pool chemicals, should never sit near a flame. Check the clearances on the rating label, and keep the area at the base open so air can reach the burner. Our garage water heater guide lists what to move.
Is it normal for a gas water heater to smell when it first fires?
A brief burning-dust smell the first time a heater runs after sitting, or right after installation, can be normal and fades fast. A rotten-egg smell is never normal: that's the odor added to gas. Get out of the house, then phone 911 and your gas company once you're outside. Don't relight or adjust anything until they clear it.
Can you convert my gas water heater from natural gas to propane?
Usually only if the maker offers a listed conversion kit for that exact model, and many don't. Converting changes the gas valve and burner orifices, and done wrong it can cause sooting or dangerous flames. In most cases, buying a heater built for your fuel is the safer path. A fuel change can also raise permit questions, so check with your city or county first.