Signs Your Water Heater Needs Attention

Water heaters are easy to forget. They sit in a closet, garage or basement corner doing one job, out of sight and out of mind, until the morning the shower runs cold or someone finds a puddle spreading across the floor. The upside is that many water heaters give some signal before they quit. You just have to know where to look, what to listen for and what a few odd smells mean.

This guide sorts the warning signs by sense: what you can see, hear, feel and smell. Some are routine maintenance issues. Others mean you should call a plumber soon, and a couple mean you should act right away.

First, know what you have

Start by finding the data label on the side of the unit. It tells you whether the heater is gas or electric, its capacity, and usually the model and serial number. Many manufacturers encode the manufacture date in the serial number. The manual or the maker's customer service line can tell you how to read it, and a plumber can too.

Age matters because tank water heaters wear out from the inside, and the manual often lists an expected service life. A heater near or past that point deserves closer attention to the signs below, and it's smart to start planning for a replacement before a failure forces a rushed decision.

Tankless units have their own tells. Since they don't store water, leaks and sediment show up differently. Watch for error codes on the display, hot water that surges and drops at certain faucets, and reduced flow. In hard water areas, mineral scale can build up inside the heat exchanger, and many manufacturers call for periodic descaling, a job plenty of homeowners hand to a plumber.

Signs you can see

Water around the base

A small puddle might come from condensation, a loose fitting or the relief valve. A tank that leaks from the body itself usually can't be repaired and needs replacement. Wipe the area dry, then check again in a few hours to narrow down where the water is coming from. If it's coming from the tank itself, call a plumber and be ready to shut off the cold water supply to the heater.

Rusty or discolored hot water

If only your hot water comes out rusty or brown, the inside of the tank or the anode rod may be corroding. If both hot and cold water are discolored, the issue may be your pipes or the water supply instead. Compare a few faucets to see which it is.

Corrosion on fittings and connections

Look at the pipes on top of the tank. Crusty white or green buildup, rust streaks and drips at the connections are worth fixing before they become leaks.

Scorch marks or soot on a gas unit

Dark marks around the burner access cover, soot, or a flame that looks yellow and lazy rather than steady and blue can point to combustion or venting problems. These can involve carbon monoxide, so have a licensed plumber or gas technician inspect it promptly, and make sure your carbon monoxide detectors work.

Signs you can hear and feel

Rumbling, popping or crackling

These sounds often come from sediment. Minerals in the water settle at the bottom of the tank, and water trapped beneath the layer boils and pops as the burner or element heats it. Sediment makes the heater work harder and can shorten its life. Flushing the tank may help, if the manual recommends it and the buildup isn't too far along.

Running out of hot water sooner

If showers go lukewarm faster than they used to, sediment may be taking up room in the tank, a heating element may have failed on an electric unit, or a part called the dip tube may be broken. It could also be that household demand has grown. A plumber can sort out which.

Temperatures that swing

Water that runs scalding one minute and cool the next may point to a failing thermostat or element. Scalding is a real safety issue, especially with young children or older adults in the house, so don't put this one off.

A relief valve that drips or releases

The temperature and pressure relief valve is a safety device that opens if the tank gets too hot or the pressure gets too high. An occasional drip can have a simple cause, but frequent discharge is a sign something is wrong. Call a plumber.

Signs you can smell

A rotten egg smell coming from the hot water only is often a reaction between bacteria in the water and the anode rod. It's unpleasant but usually not dangerous. A plumber can talk through options, such as a different anode material or treating the tank.

A rotten egg smell in the air near a gas water heater is different. That can be a gas leak. Don't flip switches, light anything or use your phone nearby. Leave the house and call the gas utility or 911 from outside.

On an electric unit, a burning or hot plastic smell near the access panels calls for turning off power at the breaker, if you can do it safely, and calling a professional.

Routine care that's reasonable for homeowners

Keep the area around the heater clear, especially around a gas unit's burner and air intake. Know where the cold water shutoff is, along with the gas valve or the electrical breaker that serves the heater.

Check the thermostat setting. Many safety organizations suggest a setting around 120 degrees Fahrenheit to reduce scald risk, but follow your manual and your household's needs.

If the manual recommends it, draining some water from the tank's drain valve can reduce sediment. Follow the manufacturer's steps carefully: the water is hot, older drain valves sometimes leak once opened, and gas and electric units need different precautions.

A drip pan under the tank, piped to a drain where possible, and a leak sensor that sends a phone notification can limit damage from a slow leak.

Leave gas connections, venting, burner work, electrical elements and wiring, and replacements to licensed pros. Replacements often need permits, and requirements for venting, expansion tanks, strapping and relief valve piping vary by state and city.

Questions to ask a plumber

• How old is this heater, and how much life do you think it has left?
• Is this leak or noise repairable, or is the tank itself failing?
• Would flushing help at this point, or could it cause new leaks?
• Is the anode rod worn, and is it worth replacing?
• Is the venting safe and up to local code?
• Do the relief valve and its discharge pipe look correct?
• If we replace it, what size and type fits our household, and what permits are needed?

Staying ahead of it

A water heater that gets a quick look once a month is far less likely to catch you off guard. For a simple routine that includes the water heater, the HVAC filter and other quick checks, HomeIsSecure's homeowner guides include a monthly walkthrough and seasonal checklists you can follow at your own pace.