Before anything else: the safety check
If you smell rotten eggs or sulfur near a gas water heater, do not flip switches, do not relight anything, and do not use your phone indoors. Leave the house, then call your gas utility's emergency line from outside. Natural gas is odorized specifically so you get this warning.
Similarly, if you see water pooling around the base of the tank, the tank has likely failed. Shut off the water supply to the heater and the power or gas to it, and call — troubleshooting a leaking tank is not worth your time because the answer is replacement.
The ordered checklist
Assuming no gas smell and no leak, these are the checks worth running yourself, roughly in the order that finds the problem fastest.
Run these in order
- 1. Electric unit: check the breaker. Water heaters often have a dedicated double-pole breaker — reset it fully off, then on.
- 2. Electric unit: press the red high-limit reset button behind the upper access panel. A tripped limit is a very common cause.
- 3. Gas unit: confirm the gas shutoff valve at the heater is open and the pilot or igniter is working per the label instructions.
- 4. Check the thermostat setting — 120°F is standard. Settings get bumped, and someone may have turned it to vacation mode.
- 5. Confirm it is not simply demand: a long shower, laundry, and dishwasher back to back will empty any tank.
- 6. Listen for rumbling or popping, which indicates heavy sediment reducing capacity rather than a hard failure.
Lukewarm instead of cold — what does that mean?
Water that is warm but never hot points somewhere different than no hot water at all. On an electric heater it usually means one of the two heating elements has failed — the remaining element still heats, just not enough. That is a straightforward repair.
On either fuel, it can also mean heavy sediment insulating the tank bottom, a dip tube that has broken and is letting cold water mix at the top of the tank, or a thermostat drifting out of calibration. A quick recovery test tells a technician which.
When should I stop and call?
Stop if the pilot will not stay lit after two attempts, if the breaker trips again after resetting, if you see any water around the base, if the water is rusty, or if you smell gas at any point. Repeated breaker trips and repeated pilot outages both indicate a real fault, and continuing to reset them stops being troubleshooting and starts being a risk.
We answer 24 hours a day, and there are no after-hours fees for True Comfort Savings Plan members. If you are without hot water in an Iowa February, that is worth a call rather than a cold weekend.
Frequently asked questions
Why does my hot water run out faster than it used to?
Usually sediment. Minerals settle on the tank bottom and occupy volume that used to hold hot water, while also insulating the water from the burner. Annual flushing helps. If flushing does not restore capacity on an older tank, the tank is likely near the end of its service life.
Is it safe to relight a gas water heater pilot myself?
On most units, yes, following the instructions printed on the heater itself — but only if you do not smell gas. If the pilot goes out repeatedly, stop relighting it. A pilot that will not stay lit usually indicates a failing thermocouple or a venting problem, and both deserve a proper diagnosis.
How long should it take to reheat a full tank?
Roughly 30 to 60 minutes for a typical gas tank and often 60 to 120 minutes for electric, depending on capacity and how cold the incoming water is. In an Iowa winter, incoming groundwater is much colder, so recovery takes noticeably longer than it does in August.
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