Smell gas? Leave the building now and call 911 from a safe place. This referral line is not an emergency service.
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No hot water? What to check first

Start with the quick checks below. Some checks take a minute; repairs are a job for a licensed plumber. Written for homeowners in Greenville, Spartanburg, Anderson and Pickens counties.

Published Sources listed at the end Checked against A. O. Smith, Ready.gov and Piedmont Natural Gas guidance

Safety first

If you smell gas (a rotten-egg smell), leave now. Don't touch switches or valves, and call 911 or your gas utility from a safe place well away from the smell. Don't use the other steps on this page if you suspect gas, and don't wait for a referral line. If water is leaking from the heater, follow our water heater leaking guide first.

1. Whole house, or one faucet?

Try the hot water at a different sink or tub. If only one faucet or shower stays cold, the problem may be in that fixture or its supply, not the water heater. Some homes have more than one water heater, so check which one serves that faucet. If no faucet gets hot water, use the steps for your heater type below.

2. Gas water heater

  • Is gas reaching the heater? If you've already noticed that your other gas appliances aren't working either, contact your gas utility. Don't light other appliances just to test. Ready.gov says that if gas service is turned off for any reason, only a qualified professional should turn it back on.
  • Is the heater's gas valve open? Only look; A. O. Smith lists gas supply problems among the common reasons a gas heater stops heating. If your utility shut off the gas, or you don't know why a valve is closed, don't open it yourself. Contact your gas utility or a licensed plumber.
  • The pilot or burner. Some gas models have a standing pilot; others ignite automatically. Use only your exact model's label and manual: A. O. Smith says its general instructions come second to the heater's own manual. Don't try to relight it if you suspect gas, the heater has been flooded, the instructions are missing, or you can't follow them safely. If it won't light or goes out again, stop and arrange service.
  • Is air getting in? A. O. Smith notes that blocked air screens or filters can keep the burner from getting enough air. Keep boxes and storage away from the heater; if a screen looks clogged, have a plumber clean it.

3. Electric water heater

  • The breaker. A. O. Smith calls a tripped circuit breaker a very common reason an electric water heater stops working. Only if the electrical panel is dry, undamaged and safe to reach, and you can identify the heater's breaker, reset it once following the panel's normal operation. If it trips again, or you notice water, damage or a burning smell, stop and contact a qualified electrician or service professional. Don't remove electrical covers.
  • The heater's own safety reset. A tripped safety reset on the heater needs diagnosis. For this checklist, don't remove the heater's access panels or touch internal wiring; contact a qualified service professional.

4. Tankless water heater

  • Check the display for an error code and follow your model's manual. Don't keep resetting it without fixing the cause.
  • If hot water comes but can't keep up, run one hot tap at a time. A. O. Smith suggests limiting simultaneous hot water use.
  • Gas ignition problems on a tankless unit are a job for a professional.

5. Hot water, but not enough

  • The temperature setting. If your model has an outside control meant for the user, check its setting with the owner's manual. A. O. Smith suggests 120°F as a balance of heating speed, energy use and safety. Don't remove access panels, and don't raise the temperature to make up for a fault.
  • Spread out the demand. Back-to-back showers, laundry and dishwashing can use hot water faster than the tank reheats.
  • Look for visible leaks or drips and report them to a plumber. A. O. Smith lists leaks, including a drain valve that isn't fully closed, among the causes. Don't operate the drain or relief valve as a test.
  • Sediment can build up in a tank and slow heating. Ask a plumber about maintenance that fits your model.

6. When to call a licensed plumber

  • There's still no hot water after the checks for your heater type.
  • The pilot won't light or stay lit, or the breaker or the heater's reset trips again.
  • Water is leaking from the tank or its fittings.

Smell gas? That's an emergency, not a plumber call: leave first, then call 911 or your gas utility from a safe place.

7. Before you call

If you can read the heater's label without moving panels or stepping into a wet or unsafe area, note the brand, model and serial number, and whether it's gas, electric or tankless. Add what you've already checked. Our call-ready planner turns that into a one-line summary. Before work starts, check the plumber's license, ask for a written estimate, and ask whether replacing the heater needs a permit (who issues plumbing permits).

8. How our referral line will work

When it opens, a short automated prompt will ask for your ZIP code. If an independent provider who serves your ZIP is available, the call will be connected. Availability isn't guaranteed, especially after hours.

We won't charge you for the referral; your phone carrier's usual rates will apply. The provider quotes the job. Not sure what to say? Get call-ready in three taps.

Sources