No Hot Water? A Troubleshooting Guide

Nothing ruins a morning like a cold shower. The good news is that "no hot water" often has a simple cause you can check in a few minutes. This guide walks through safe checks for gas and electric water heaters, in the right order. If the checks don't solve it, our water heater repair team in Newark can help 24/7.

Safety first: If you smell gas, don't touch anything. Leave the house and call your gas utility or 911 from outside.

Step 1: Is it the whole house or one tap?

Turn on the hot water at two or three faucets in different rooms.

• No hot water anywhere: the problem is the water heater. Keep reading.
• No hot water at one tap only: the faucet's cartridge or a shower mixing valve is the likely cause.
• Hot water runs out fast: see Step 6.

Step 2: Gas water heater checks

Is the gas on?

Check that other gas appliances, like the stove or furnace, work. If none do, call your gas utility. Also make sure the gas shut-off valve on the pipe going to the heater is open (handle parallel to the pipe).

Is the pilot lit?

Older tanks have a small window or access cover where you can see the pilot flame. Newer sealed models have a glass sight window.

• Pilot out: follow the lighting instructions on the label. If it won't stay lit, read water heater pilot light won't stay lit.
• Pilot lit, but no burner: check the temperature dial. Someone may have turned it to "Vacation" or "Low."

Does the heater have an electronic ignition?

Some newer gas tanks plug into an outlet and use electronic ignition or power venting. Check that the plug is in, the outlet works and the GFCI hasn't tripped. Look for a blinking status light and check the code in the manual.

Is the flame arrestor clogged?

Many newer tanks have a screen at the bottom that lets air in. Lint and dust can clog it, especially if the heater is near a dryer. A clogged screen can starve the burner of air and shut it down. Cleaning it is a job for a pro on most models.

Step 3: Electric water heater checks

Did the breaker trip?

Find the double breaker for the water heater in your panel. If it is tripped, reset it once. If it trips again, stop and call a pro. Something is shorting out.

Did the high-limit switch trip?

Electric heaters have a red reset button behind the upper access panel. It trips if the water gets too hot.

1. Turn the breaker off first.
2. Remove the upper access panel and move the insulation aside.
3. Press the red reset button firmly.
4. Replace the insulation and cover, then turn the breaker back on.

If it trips again, a thermostat or element has failed.

Is the thermostat set correctly?

Thermostats are behind the access panels, so check them only with the power off. About 120°F is right for most homes.

Step 4: Heat pump water heater checks

Check the display for an error code or a mode setting. If it is in "Vacation" mode, switch it back. A dirty air filter or a blocked condensate drain can also stop it. Check the manual for steps.

Step 5: Tankless water heater checks

• Check the display for an error code and look it up in the manual.
• Make sure the gas and power are on.
• Clean the inlet water filter. A clogged filter can stop the unit from firing.
• Make sure you are running enough flow. Very low flow may not trigger the burner.
• If it has been more than a year, the heat exchanger may need descaling.

Step 6: Hot water, but it runs out fast

In Delaware, incoming water is much colder in January than in July, so heaters take longer to recover in winter. A heater that barely kept up in summer may fall short in winter.

A flush can help with sediment. Element and dip tube problems need a repair.

Quick reference: symptoms and causes

How to prevent a no-hot-water morning

• Flush tanks yearly so sediment does not bury the lower element or smother the burner.
• Keep the closet clear around gas heaters so lint does not clog the flame arrestor.
• Descale tankless units on the maker's schedule.
• Clean heat pump filters every 6 to 12 months.
• Replace aging tanks before year 12 or so.

Local note: Gas tanks next to a dryer are common in Pike Creek and Bear townhomes, which makes lint-clogged burners a frequent cause. Electric tanks in Middletown homes on harder water lose lower elements faster.

Related reading: If the pilot is the problem, see why a water heater pilot light won't stay lit. If the tank is old, read the signs your water heater is going out.

When should you call a water heater professional?

Call a pro if:

• You smell gas
• The pilot won't stay lit after one relight
• A breaker or reset button keeps tripping
• There is water around the heater
• The simple checks don't bring your hot water back

No hot water in Newark? Call (302) 732-0874 for water heater repair from Newark Heater Pros, 24/7.