No Hot Water
Follow these steps before calling a plumber — 60% of no-hot-water calls are simple fixes.
Look, don't relight from this page
A viewport on many gas tanks shows whether a pilot flame is present. If it is out, use only the lighting steps printed on the unit. This guide does not include a lighting procedure.
A pilot that will not stay lit
The usual cause is a worn thermocouple or the gas control. That is a repair, not a parts-swap you do from a web page. The diagnostic visit is $150, waived if you proceed with the repair.
Check the temperature dial you can see
Confirm the control is not on vacation or a very low mark. If the burner still will not fire, stop. A faulty gas control is a licensed-plumber job.
Other gas appliances
If the furnace, range, and dryer are out too, call the gas utility. Do not open or adjust the supply piping to the water heater.
Reset the breaker once
Electric tanks use a dedicated double-pole breaker. If it is tripped, switch it fully off, then on, one time. Wait for the tank to reheat. If it trips again, stop.
Leave the covers on
The high-limit reset, heating elements, and thermostats are behind access panels on a 240-volt circuit. This page does not include steps for opening those panels, metering elements, or replacing thermostats.
- Gas smell anywhere near the unit (gas leak — evacuate first)
- Pilot relights but trips every few hours (failing thermocouple or gas valve)
- Breaker trips repeatedly after reset (short circuit in element or wiring)
- Water heater is over 12 years old and suddenly stopped working
- Loud popping or rumbling from the tank (severe sediment — likely time to replace)
- Visible rust or corrosion on the tank body
Leaking Water Heater
Where the water comes from tells you exactly how serious it is. Location first, then action.
🚨 Do this before diagnosing — active leak emergency steps
- Turn off the cold water supply. Find the cold water inlet valve at the top of the tank. Turn it clockwise (or flip the lever) to shut off water flow to the heater.
- Shut off the energy source. Gas: turn the gas control valve to "Pilot" or "Off." Electric: flip the dedicated circuit breaker to OFF.
- Clean up standing water to prevent floor damage and mold. Then identify where the leak is coming from before calling us.
Diagnose by location
Top of the tank Often fixable
- Cold water inlet pipe connection loose
- Hot water outlet pipe connection loose
- Anode rod port fitting corroded
T&P valve (side of tank) Usually fixable
- T&P (temperature & pressure relief) valve weeping or dripping
- Discharge pipe has water on it
Bottom (drain valve area) Usually fixable
- Drain valve handle cracked or loose
- Valve seat corroded after years without use
Bottom (tank body) Replacement needed
- Water pooling directly under tank
- Rust-colored water or staining on floor
- Tank body visibly corroded or bulging
Even "minor" leaks cause floor rot, mold, and structural damage fast. A slow drip from a failing tank liner can become a flood in hours. Don't wait on this one. Emergency free quotes and scheduling →
In humid weather or during the first use of a new unit, you may see moisture on the outside of the tank. Wipe it dry, check again in an hour. True leaks produce a puddle or wet spot that returns. Condensation doesn't.
Strange Noises
Rumbling, popping, or screeching? Here’s what each sound means and how to fix it.
What the noise tells you
Rumbling / Banging Sediment buildup
- Low-frequency rumbling as unit heats
- Popping or boiling sounds inside the tank
- Water takes longer to heat than before
Popping Mineral deposits
- Tinny, high-pitched popping from the tank
- Often most audible when hot water is running
Whining / Screeching Scale restriction
- High-pitched sound at the top of the tank
- Often when hot water first starts flowing
High-Pitched Whistling T&P valve
- Whistling or hissing from the T&P valve discharge pipe
- May be accompanied by dripping water
How to drain and flush a gas water heater
Turn off the gas
Rotate the gas control valve to the “Off” position. This stops the burner from running while you’re working on the plumbing.
Close the cold water inlet valve
Turn the valve at the top of the tank clockwise until it stops. Prevents fresh water from entering while you drain.
Open a hot water faucet in the house
Turn on a sink or shower in the house on hot. This breaks the vacuum and lets the tank drain properly.
Connect a garden hose to the drain valve
Attach a standard garden hose to the drain valve at the bottom of the tank. Run the hose outside to a floor drain, driveway, or lawn.
Open the drain valve
Turn the drain valve counter-clockwise. Water will begin flowing out — watch for the first few gallons to be dark brown if sediment is heavy.
Fill the tank and repeat if needed
Close the drain, reopen the cold inlet valve to refill the tank, then drain again. Two flushes removes most sediment. Three if water was very dark.
Close the drain and refill
Disconnect the hose, close the drain valve, and open the cold-water inlet. Restore heat only by the positions printed on the unit. Do not light the burner with a lighter. If you smell gas, stop and leave the house.
Sediment buildup that comes back within weeks, or noises from a tank older than 10 years, likely means the tank interior is heavily corroded. The fix at that point is replacement — see replacement options →
Pilot Light Won’t Stay Lit
The pilot flame is the most common failure point in gas water heaters. Here’s why it goes out and how to fix it.
What’s most likely causing it
Thermocouple failure — the usual cause
The thermocouple sits in the pilot flame and tells the gas control to stay open. When it wears out, the control shuts the pilot off. Replacing it means working on the gas control. That is a repair visit, not a home project. The diagnostic is $150, waived if the repair goes ahead.
A weak pilot flame
Dirt in the pilot opening can starve the flame. Cleaning that opening is work on the gas train. Do not blow it out, poke it, or take the control apart. Call a licensed plumber.
Gas supply issue
Check whether other gas appliances in your home are working — the furnace, stove, dryer. If nothing gas-powered works, your supply may be interrupted. Call your gas utility. Low gas pressure from the main can also cause a pilot to light but not stay lit.
Drafts and the vent
A strong draft can blow a pilot out, and a damaged or missing vent is a combustion-safety problem. Do not install, reseal, or replace a draft hood or vent pipe. That is venting work for a licensed professional, and it can require a permit.
Rusty or Discolored Water
Rust-colored, cloudy, or foul-smelling water each point to a different cause — some are simple fixes, some signal tank failure.
Hot water only is rusty — failing anode rod
If cold water runs clear but hot water looks orange or brown, the problem is inside your tank. The anode rod is a sacrificial magnesium or aluminum rod that corrodes instead of the tank lining. When it's depleted, the tank itself starts to corrode. Replace the anode rod every 2–3 years ($20–$50 part, DIY-possible with a 1-1/16" socket). Replacing it early is one of the best things you can do to extend tank life.
Both hot AND cold water are rusty — supply pipe issue
If rust appears in both hot and cold water, the water heater isn't the culprit — the problem is in the supply pipes coming into your home. This is common in older homes with iron or galvanized steel pipes. Contact your city utility to rule out a water main problem, then have a plumber inspect your supply lines.
Milky or cloudy water — dissolved minerals
White or cloudy water is caused by dissolved minerals (usually calcium and magnesium) coming out of solution at high temperatures. It's not dangerous. The fix: lower your thermostat to 120°F. At that temperature, mineral precipitation slows significantly. A water softener addresses the underlying cause if you're in a hard-water area.
Rotten egg smell — bacteria in the tank
A sulfur or rotten egg odor is caused by bacteria reacting with the hydrogen gas produced by the anode rod. More common in homes with well water or after a unit sits unused. First try: flush the tank thoroughly with a dilute hydrogen peroxide solution (1–2 pints to a full tank). Second fix: switch to an aluminum/zinc alloy anode rod, which produces less hydrogen than magnesium rods. Third option: install an inline filter or UV purifier if bacterial contamination persists.
A depleted anode rod is fixable. But if rust is seeping through the tank body itself — visible corrosion on the outside, rust-colored water despite a fresh anode rod — the internal lining has failed. This tank needs replacement. No repair will stop internal tank corrosion. See replacement options →
Water Too Hot or Not Hot Enough
Temperature problems usually have a simple root cause. Here's how to diagnose and fix both extremes.
Check the thermostat setting
The most common cause of scalding water is a thermostat set too high. The Department of Energy recommends 120°F for most households. On a gas water heater, use the dial on the front of the control if it is already exposed. Do not open the electric access panels to reach a thermostat. That is wiring work.
Check the T&P valve if water is continuously too hot
If the thermostat is set correctly but water is still scalding, the thermostat may have failed in the "on" position, causing the element or burner to run continuously. This also stresses the T&P valve. If the T&P valve is weeping or hissing, excess pressure is confirming the thermostat is stuck. This requires a pro — don't ignore a stuck-open thermostat.
Fluctuating temperature
If water temperature swings between hot and cold during a single shower, the cause is usually a mixing valve issue (if your shower has a mixing valve), or competing hot water demand — multiple fixtures running simultaneously depleting the tank faster than it can recover. Try staggering hot water use. If a single fixture fluctuates alone, the mixing cartridge in that fixture may need replacement.
Check the thermostat setting first
Look at the dial on the front of a gas control if one is already exposed. Do not open electric access panels to adjust upper and lower thermostats. If the water stays lukewarm after a single breaker reset, call for repair.
Dip tube diagnosis
If you get short bursts of hot water followed immediately by cold, the dip tube is likely broken. The dip tube is a plastic tube that carries incoming cold water to the bottom of the tank so it heats from below. A broken dip tube dumps cold water at the top, where it immediately mixes with hot outgoing water. Signs: alternating hot/cold in short cycles, plastic fragments occasionally coming from faucets. A replacement dip tube is a $10–$20 part, but installation requires draining the tank and accessing the cold inlet fitting — a one-hour plumber job.
Slow recovery — sediment buildup
If you run out of hot water faster than before, or the tank takes noticeably longer to reheat after a shower, sediment has likely accumulated at the bottom of the tank. Sediment acts as an insulating layer, reducing the effective heating volume and making the element or burner work much harder. Fix: flush the tank (see the 7-step flush in Section 3). Annual flushing prevents this from accumulating.
Tank undersized for household demand
If the tank runs out of hot water consistently, especially after the household has grown, the tank may simply be too small. A 40-gallon tank supports roughly 2–3 people; 50–80 gallons for 4–6 people. Consider a larger tank or switch to a tankless water heater for continuous on-demand hot water. See tankless options →
If setting the thermostat to 120°F doesn't resolve the problem — water is still scalding or still cold — the thermostat itself has likely failed. A failed thermostat on an electric unit can also cause a heating element to burn out. Similarly, if you suspect a broken dip tube or a failed heating element, these require a pro. Schedule a repair →
Can't figure it out?
Get a free diagnosis.
Request a quote and we'll connect you with a licensed plumber fast. Call or text (918) 417-8981.
Get Free Diagnosis →