Water heater troubleshooting
No Hot Water? Water Heater Troubleshooting for Fort Collins Homes
Quick checks for gas and electric water heaters, what the symptoms mean, and when it's time to call a licensed plumber.
Updated November 2026
Smell gas? Leave the house now and call 911 or your gas utility from outside. Water leaking? Shut off the cold-water valve above the heater and turn off the gas or breaker.
Gas water heater: no hot water
Check the pilot or burner
Look through the sight glass near the bottom of the tank. If there's no flame, relight the pilot by following the instructions on the label. Newer units with electronic ignition may show a blinking status light instead.
Pilot won't stay lit
A worn thermocouple or flame sensor is the most common cause ($150–$350 to replace). Drafts, a blocked vent or a failing gas control valve can also be to blame.
Check the temperature dial
Make sure it wasn't bumped to “Vacation” or “Low.” About 120°F is a common setting.
Electric water heater: no hot water
Check the breaker
Water heaters use a double-pole breaker. If it's tripped, reset it once. If it trips again, stop and call a plumber or electrician.
Press the high-limit reset
With the power off, remove the upper access panel and press the red reset button. If it trips again soon, the thermostat or an element has likely failed ($150–$450).
Lukewarm water only
A failed lower element often leaves you with a small amount of warm water that runs out fast.
Other symptoms
| Symptom | Likely cause | What to do |
|---|---|---|
| Water pooling under the tank | Corroded tank, drain valve or T&P valve | Shut off the water; a tank leak means replacement |
| Popping or rumbling | Sediment on the bottom of the tank | Flush the tank; sooner is better |
| Rotten-egg smell | Anode rod reacting with the water | Replace the anode rod |
| Rusty hot water | Tank corrosion or a spent anode rod | Have the tank inspected |
| Runs out fast | Sediment, broken dip tube, failed element or undersized heater | Diagnose before replacing |
No hot water questions
Why do I suddenly have no hot water?
On a gas water heater, the usual causes are a pilot light that went out, a worn thermocouple or flame sensor, a failed igniter or a bad gas control valve. On an electric heater, check for a tripped breaker or a tripped high-limit reset button, then a burned-out element or thermostat.
How do I reset my water heater?
Electric heaters have a red high-limit reset button behind the upper access panel. Turn off the breaker first, remove the panel and press the button. If it trips again, call a plumber; it usually means a failed thermostat or element. Gas heaters don't have a reset button; relight the pilot following the label on the tank.
Is a leaking water heater an emergency?
A leak from the tank body is serious because the tank can't be repaired and may fail further. Turn off the cold-water supply valve, turn off the gas or power, and call a plumber. Leaks from the drain valve, T&P valve or fittings are often fixable.
What should I do if I smell gas near my water heater?
Don't light anything or flip switches. Leave the house right away and call 911 or your gas utility's emergency line from outside. Don't go back in until it has been checked.