Water heater problems

No hot water at all. On an electric unit, this is most often a tripped breaker, a tripped high-limit reset, or a dead upper heating element. On a gas unit, the pilot or igniter has failed or the gas control valve has. All of these are diagnosable in a normal service call.

Water in the drip pan or on the floor. Find out where it is coming from before you panic. A dripping temperature and pressure relief valve or a leaking supply connection is a repair. Water seeping from the bottom of the tank body itself is a failed tank, and that means replacement. There is no patch for a rusted tank.

Rumbling, popping, or banging. That is sediment on the tank floor, with water boiling underneath it. It reduces capacity, wastes energy, and shortens tank life. Flushing helps; if it has been ignored for years, it may not fully clear.

Anything involving gas smell, soot, or a CO alarm is not a plumbing problem — it is an evacuate-and-call problem. Leave the house, then call your gas utility's emergency line from outside. CPSC has recalled gas tankless water heaters for carbon monoxide hazards, including a 2026 recall of VST-brand units, so a CO issue traced to a water heater is not a far-fetched scenario. Never troubleshoot combustion or venting yourself.

How to choose

Locate the leak before you accept a diagnosis

Top-of-tank fittings and the T&P valve are repairable. The tank body is not. A contractor should be able to show you which it is.

Note the unit's age before you spend on repair

There is a date code on the data plate. NerdWallet puts tank life at roughly 10-15 years. Repairing a 14-year-old tank rarely pays.

Treat lukewarm water on a gas unit as a real symptom

It can be sediment, a failing dip tube, or a partly failed gas valve. Do not just crank the thermostat up — that raises scald risk without fixing the cause.

Smelly hot water is usually the anode rod

A rotten-egg smell in hot water only is typically bacteria reacting with the magnesium anode. It is a known, fixable issue — ask about an anode rod change rather than replacing the heater.

Never bypass or cap a T&P valve

If the temperature and pressure relief valve is discharging, something is wrong with pressure or temperature. Capping it turns a nuisance into a genuine explosion hazard. Get it diagnosed.