What Are the Signs Your Water Heater Is Going Bad?

Water heater with hose attached

Unexpected Water Heater Issues

It is one of those things that happen unexpectedly for most of us, and usually at an inconvenient time. The hot water heater quits heating water, or even worse, leaks water, flooding the basement, garage, or hall closet. Was there something telling you this was about to happen that a water heater repair could have prevented?

Can you get your water heater repaired or does it need to be replaced?  

If water heater repairs are possible, do plumbers fix water heaters? Yes, sometimes water heater repairs are possible, especially if the unit is less than 10 years old.  And yes, most plumbers can do water heater repairs. When you call to request water heater repair, they will advise you if they offer that service.

Most homeowners will replace a water heater when they have any trouble, like a water heater is not heating enough water.  Sometimes, a problem like that, water heater repairs are possible though. You need to have some basic understanding how a water heater works first to realize when water heater repairs are possible and when they need to be replaced. 

Water heaters are powered by either electricity or gas. Otherwise, how their basic functions work is similar. An overview of an electric water heater working: 

The Electric Water Heater

An electric water heater has a thermostat, a T&P valve (temperature pressure relief valve), a drain valve, an anode rode, and an insulated tank. Cold water enters an electric water heater through the dip tube. There are 2 electric elements inside the tank that heats that water. As the water heats, it rises inside the tank and is moved through the plumbing to where a hot water faucet is opened. 

The Gas Water Heater

A gas-powered water heater has a little more going on inside but works pretty much the same way as the electric water heater.  The cold water comes into the tank through the dip tube, but a gas burner heats the water instead. 

This gas burner releases an extremely hot, toxic air up through the chimney that comes out of the water heater tank top.  That toxic air is released outside as the chimney and the water surrounding the chimney inside the tank heats up. 

Like the electric water heater, as the heat rises, the heated water goes through the plumbing and is dispersed to open hot water faucets at the temperature you have the thermostat set, pulling power from the connected gas line. 

Additional Notes: 

All water heaters have protective measures like the T&P valve (the temperature and pressure-relief valve) that opens and releases water when the water temperature is too hot or there is too much pressure inside the tank. The T&P valve is what keeps the water tank from exploding. Over time, the T&P valve goes bad and is a common water heater repair. 

The tank on all water heaters is insulated inside. This keeps the water warm for a period and keeps the exterior from getting hot to the touch. All water heaters have an anode rod that is made of a metal. This part of a water is sacrificed because it will rust itself, preventing the water tank from rusting. When the water is coming from the faucets rusted looking, this is an indicator that a water heater repair to replace the rod is needed – usually every 2 years depending on the water quality. 

Another common water heater repair is the drain valve. This is located on the side of all water heaters tank. The tank should be drain of all water inside the once a year and flushed using a water hose. This removes the sediment build-up that is common for any water heater. 

Can I flush my water heater myself?

Absolutely, the owner’s manual will have instruction on the process. The typical steps is to connect a garden water hose to the drain, turn the hot water valve at the water heater on and let it run until the water is no longer rusty. If the water keeps coming out rusty, you should have a professional plumber inspect the unit, many any possible water heater repairs, like replacing the anode rod. Or they may recommend a new water heater instead, which will often be because of the age of the unit. 

What makes a water heater smells like sulfur? 

When a water heater is smelling like sulfur, that is a bacterium releasing inside the tank. Sulfate-reducing bacteria is caused by small amounts of hydrogen being released. It is harmless health-wise, but the odor is unpleasant. 

When you notice this rotten egg smell, turn on cold water at each faucet. If that odor isn’t coming out with the cold water, the problem is your water heater has stagnant water inside the tank. You can DIY water heater repair by flushing it out as we describe above. If that doesn’t get rid of the smell, call a plumber for a professional assessment and water heater repair. If your water heater is around 12 years old, they will typically recommend a new water heater. 

If you are on a water well system, it could be a matter of bacteria and sulfur in the water itself. There are water purifiers to help with this that can be professional installed or DIY installation. If you have a water softener system in place, and the anode rod is made of magnesium, a professional plumber and replace it with an anode rode bad of aluminum and zinc, the odor will dissipate. 

What does it mean when water heater is leaking from bottom? 

When your water heater is leaking from the bottom, you have a serious issue that could be any of the following three things: 

  • Drain Valve Broke: Located to the side near the bottom of the tank is a drain valve. Over time, these become clogged and rusted with residue from the water. If the water is leaking from this, a water heater repair is possible by replacing the drain valve. 
  • T&R Valve: The Temperature and Pressure Relief Valve releases pressure from the tank if it has too much or if the water inside the tank gets too hot. If you notice water leaking close to the bottom of the water heater, inspect the discharge pipe. If there is water there, the T&R Valve needs to be replaced, which requires a professional water heater repair. 
  • Water Tank Damaged:  There could be a possible internal issue with the water heater tank developing a leak, usually from a build-up of sediment. If the water tank hasn’t ever been drained and flushed, that build-up of minerals will rust the tank, cracks and holes develop, and water begins to leak. At that point, a water heater repair isn’t possible, you’ll need a new water heater. 

How long do water heaters last?

The quality of the water system you have, and the quality of the water heater will make a difference.  With poor water quality a low-end water heater, 5 to 6 years is an average lifetime. With good water quality and a good quality water heater, you can get 12 to 15 years when proper maintenance is followed (flushing). At 10 years, you’re on borrowed time no matter the quality of the water or water heater. 

Can a water heater explode?

It is rare, but yes, water heaters will explode.  If you notice any of the following, schedule a water heater repair and inspection immediately: 

  • T&R Valve Leaking
  • Knocking & Rattling Sounds from Water Heater Tank
  • Rotten Egg Odor

A poor water heater installation job can cause a water heater to explode too. Which why having it installed by a professional instead of doing it yourself is recommended. 

Modern Water Heater

When Water Heater Repair Isn’t Possible


So, the plumber tells you your water heater is done and you need to replace the unit. Which water heater is best? Choose a water heater that offers the following features: 

  • Warranty: Three years is average, the better water heaters will have a 10-to-12-year warranty. These cost more but are worth if you can afford that upgrade. 
  • Anti-scale device: This is supposed to reduce mineral scale buildup at the bottom of the tank. That scaling process shortens the life of the heating element, and most 12-year warranty water heaters have this feature built-in. 
  • Brass vs. plastic drain valve: Choose the unit with a brass drain valve. 
  • Glass-lined tank: Corrosion is reduced with these water heaters, again, the higher-end is more likely to have this feature, with a 12-year warranty.
  • Digital display: This can help you monitor the different levels and customize the operation of your water heater, like vacation mode.

If you think you may need water heater repair or replacement, give us a call at (508) 272-1196.